Miniature Ball Bearings

1
 Contents Bearing tables
Page

Technical information Contents .......................................................................................... 31

Page
1. Bearing types and features ..................................................... 8 Appendices

2. Formulation of bearing numbers ............................................ 12 Contents .......................................................................................... 53

3. Cage design .............................................................................. 14 Appendix 1 Conversion from SI (International Units) system ............ 54
Appendix 2 N – Kgf conversion table ............................................... 56
4. Selection of bearing size ......................................................... 14 Appendix 3 Kg – 1b conversion table ............................................... 57
4.1 Bearing life .............................................................................. 14 Appendix 4 °C – °F conversion table ............................................... 58
4.2 Basic load rating and fatigue life .............................................. 14 Appendix 5 Viscosity conversion table ............................................. 59
4.3 Static load rating and static equivalent load ............................. 16 Appendix 6 Inch – mm conversion table .......................................... 60
Appendix 7 Hardness conversion table ........................................... 61
5. Limiting speeds ........................................................................ 17 Appendix 8 Values of standard tolerances grades IT ....................... 62
Appendix 9 Physical and mechanical properties of materials ........... 64
6. Bearing tolerances ................................................................... 17
Bearing conversion tables
7. Fits and internal clearances .................................................... 22
7.1 Shaft and housing fits .............................................................. 22 Contents .......................................................................................... 65
7.2 Bearing internal clearances ...................................................... 25

8. Lubrication ................................................................................ 26
8.1 Purposes of lubrication ............................................................ 26
8.2 Lubricating methods and lubricants ......................................... 26

9. Bearing materials ..................................................................... 28

6 7
 Miniature and instrument ball bearings can be divided into that is larger than normal compared with the bearing width.
two basic types, deep groove and angular contact. The first • Thin section type in which both rings are extra thin in the
(deep groove) can be further divided into the following five radial direction.
classes depending on their design details: Deep groove ball bearings can also be classified as “Open”,
• Standard type “Shielded”, or “Sealed” depending on the existence and
• Flanged outer ring type of seal or shield. The size ranges of extra small and
• Extended inner ring miniature ball bearings are shown in Table 1.1.
• Expanded type in which one ring has a radial thickness

Deep groove ball bearings have two inherent advantages;

they can sustain some axial load in either direction as well as
radial loads, and the two raceway cross-sections are simple
circular arcs which can be very precisely finished so the
bearings have low friction and very little noise or vibration.
Several different cage designs are available with different
characteristics and the choice depends upon the individual
application.

Deep groove ball bearings with flanged outer rings

correspond to ordinary ball bearings with snap rings. The
flange extends around the entire circumference of the outer
ring due to the size limitation and to improve its running
accuracy. Since it is not necessary to provide a shoulder on
the housing bore if this bearing is used, the bore can be a
simple cylindrical shape which facilitates high precision
machining and also reduces the machining time.

8 9
11
 2. Formulation of bearing
numbers
Bearing numbers are alphanumeric combinations that indicate NSK uses auxiliary symbols other than those specified by JIS. Examples of bearing numbers
the bearing type, boundary dimensions, internal clearance, Basic numbers, supplementary symbols, and the meanings of (1) 68 1X T12 ZZ MC3 P4 L UC3 AF2 Q 681XT12ZZMC3P4LUC3 AF2Q
dimensional and running accuracies, and other related specifi- common numbers and symbols are listed in Table 2.1 (2) 62 4 h ZZ MC2 E P5 NS7 L 624hZZMC2EP5 NS7L
cations. They consist of basic numbers and supplementary (Pages 12 and 13). The contact angle symbols and other (3) S MR 84 W ZZ MC3 P5 UC1 PS2 L SMR84WZZMC3P5UC1 PS2L
symbols. The boundary dimensions of commonly used supplementary designations are shown in successive columns
(4) S MF 148 J MC4 P5 L SMF148JMC4P5L
bearings mostly conform to the organizational concept of from left to right in Table 2.1. For reference, five examples of
ISO, and the bearing numbers of these standard bearings bearing numbers are shown on Page 13. (5) S R 2 J ZZ MC3 7P NS7 K SR2JZZMC37P NS7K
are specified by JIS B 1513 (Designation for rolling
bearings). Due to a need for more detailed classification,

Table 2.1 Formulation of bearing numbers

Basic numbers Supplementary number

Special specification Lubricant quantity

Bearing series symbols Bore number or size number Contact angle symbol Internal design symbol Material symbol Cage symbol Seals, shields symbol Internal clearance symbol Noise level symbol Accuracy class symbol Torque symbol Lubricant symbol
symbol symbol

Meaning
Symbol Meaning Number Meaning Symbol Meaning Symbol Meaning Symbol Meaning Symbol Meaning Symbol Meaning Symbol Symbol Meaning Symbol Meaning Symbol Meaning Symbol Meaning Symbol Meaning Symbol Meaning
(radial clearance)

68 Single-row deep groove 1 Bearing bore 1 mm (Angular A Internal Omitted High carbon J Pressed steel Z Shield MC1 Clearance less than MC2 Omitted Standard Omitted Normal Omitted Standard U1 Special AF2 AEROSHELL Q Oil soaking
ball bearings contact ball design differs chromium ribbon cage on one side specification FLUID 12
69 (Omitted) Z1
bearings) B from standard bearing steel only
60 2 Bearing bore 2 mm one SUJ 2 MC2 Clearance less than MC3 E Quieter than P6 Class 6 L Low torque K Grease
Equivalent to standard U2 NS7 NS HI-LUBE packed less
62

...
A Standard ASTM A295 ZZ Shields on than L
63 3 Bearing bore 3 mm
contact angle 52100 both sides MC3 Upgrade normal clearance P5 Class 5
ZZ1 Quieter than PS2 MULTEMP
...

of 30° ER
F68 Deep groove ball bearings h Stainless E PS No.2 L Standard
with flanged outer rings steel D Contact MC4 Clearance greater than P4 Class 4 UC1 Bore diameter grease
F69 1X Bearing bore 1.5 mm Standard rubber seal MC3 is sorted into packing
A5 Equivalent to W Pressed steel
F60 contact angle on one side two groups quantity
SAE J405 snap cage
Bearing bore 2.5 mm of 25° (Omitted) only Omitted ANSI/
F62 2X 51440C
MC5 Clearance greater than ABMA
F63 MC4 UC2 Outside
...

ABEC 1 S Grease
B Standard T12 Plastic snap DD Contact diameter is packed more
S Stainless sorted into
contact angle steel for T1X cage rubber seal than L
70 Single-row angular two groups
contact ball bearings of 40° special metric on both side MC6 Clearance greater than 3 ANSI/
MC5 ABMA
72 and inch
designs “S”
ABEC 3 H Grease
C Standard V Non-contact UC3 Both bore packed more
is prefix to and outside
contact angle series symbol rubber seal than S
of 15° on one side 5P ANSI/ diameters are
Special metric design only ABMA sorted into
Instrument two groups M Grease
MR Single-row deep groove 84 Brg O.D. 8 mm ball bearings packed more
ball bearings Brg bore 4 mm VV Non-contact inch design than H
148 Brg O.D. 14 mm rubber seal CLASS 5P
Brg bore 8 mm on both side
...

MF Deep groove ball bearings

with flanged outer rings
7P ANSI/
41X Brg O.D. 4 mm ABMA
Brg bore 1.2 mm
SMT Thin-section deep groove Instrument
ball bearings 82X Brg O.D. 8 mm ball bearings
Brg bore 2.5 mm inch design
...

CLASS 7P

Inch design 9P ANSI/

ABMA
R Single-row deep groove 133 Brg O.D. 4.762 mm Instrument
ball bearings (3/16 inch) ball bearings
Brg bore 2.380 mm
inch design
(3/32 inch)
SR...X Ball bearings for synchros CLASS 9P When selecting these specifications
155 Brg O.D. 7.938 mm please consult NSK
(5/16 inch)
RW Deep groove ball bearings Brg bore 3.967 mm
with extended inner rings (5/32 inch)
2 Brg O.D. 9.525 mm
(3/8 inch)
...

FRW Deep groove ball Brg bore 3.175 mm

bearings with extended inner (1/8 inch)
rings, flanged

12 13
Selection of bearing size

The L10 life is defined as the rating fatigue life with a It is very rare for extra small and miniature ball bearings to fail 5. Limiting speeds 6. Bearing tolerances
statistical reliability of 90 %. Depending on the machines in because of fatigue. Other problems such as wear,
which the bearings are used, sometimes a reliability higher reduced accuracy, or deterioration of the grease define the The speed of rolling bearings is subject to certain limits. The tolerances for the boundary dimensions and running
than 90 % may be required. However, recent improvements limit of bearing life instead of flaking. This is particularly true When bearings are operating, the higher the speed, the accuracy of extra small and miniature ball bearings are
in bearing material have greatly extended the fatigue life. In of audio-visual equipment in which extra low noise and higher the bearing temperature due to friction. The limiting specified by ISO 492/582 (Rolling bearings-radial bearings
addition, the development of the Elasto-Hydrodynamic Theory vibration, low torque, or other requirements are highly speed is the empirically obtained value for the maximum tolerances) and ANSI/ABMA Std. 12.2 (Instrument ball
of Lubrication proves that the thickness of the lubricating film important. The elapsed time when a bearing fails to satisfy its speed at which bearings can be continuously operated bearings inch design). Tables 6.1, 6.2 and 6.3 apply to
in the contact zone between rings and rolling elements functional requirements may be regarded as bearing service without failing from seizure or generation of excessive heat. metric design extra small and miniature ball bearings.
greatly influences bearing life. To reflect such improvements life. Consequently, the limiting speed of bearings varies Tables 6.4 and 6.5 apply to inch design extra small and
in the calculation of fatigue life, the rating fatigue life is depending on such factors as bearing type and size, cage miniature precision ball bearings for instruments.
corrected using the following correction factors: form and material, load, lubrication method, and heat Bearing accuracy should be chosen depending on the
4.3 Static load rating and static dissipating method including the design of the bearing’s application. A rough guide for the selection of bearing
Lna = a1 a2 a3 L10 ................................. (4.7) equivalent load surroundings. The maximum permissible speed for contact accuracy is presented in Table 6.6.
rubber sealed bearings (DD type) is determined mainly by
When subjected to an excessive load or a strong shock load,
where Lna : Adjusted rating life in which reliability, material the sliding surface speed of the inner circumference of the
rolling bearings may incur a local permanent deformation of
improvements, lubricating conditions, etc. are seal. Symbols for boundary dimensions and running
the rolling elements and raceway surface if the elastic limit is
considered Values for the limiting speed of bearings lubricated by grease accuracy
exceeded. The nonelastic deformation increases in area and
and oil are listed in the bearing tables. The limiting speeds in d Brg bore dia., nominal
depth as the load increases, and when the load exceeds a
L10 : Rating fatigue life with a reliability of 90 % the tables are applicable to bearings of standard design that d ds Deviation of a single bore dia.
certain limit, the smooth running of the bearing is impeded.
a1 : Life correction factor for reliability are subjected to normal loads, i.e, C/P12 and F a /Fr0.2 d dmp Single plane mean bore dia. deviation
The basic static load rating for deep groove ball bearings is
a2 : Life correction factor for material approximately. The limiting speeds for oil lubrication listed in Vdp Bore dia. variation in a single radial plane
defined as that static load which produces 4200 MPa
a3 : Life correction factor for operating conditions the bearing tables are for conventional oil bath lubrication. Vdmp Mean bore dia. variation
{428 kgf/mm2} contact stress at the center of the contact
When speeds are more than 70 percent of the listed limiting
area between the rolling element subjected to the maximum
The life correction factor for reliability a1 is listed is Table 4.2 speed, it is necessary to select an oil or grease which has D Brg outside dia., nominal
stress and the raceway surface.
for reliabilities higher than 90 %. good high-speed characteristics. d Ds Deviation of a single outside dia.
In this most heavily stressed contact area, the sum of the
When the required speed exceeds the limiting speed of the d Dmp Single plane mean outside dia. deviation
permanent deformation of the rolling element and that of the
desired bearing, then the accuracy grade, internal clearance, VDp Outside dia. variation in a single radial plane
raceway is nearly 0.0001 times the rolling element’s diameter.
cage type and material, and lubrication, must be carefully VDmp Mean outside dia. variation
The basic static load rating, Co, is written “Cor” for radial
studied in order to select a bearing capable of the required D1 Outside dia. of the outer ring flange, nominal
Table 4.2 Reliability factor a1 bearings in the bearing tables.
speed. If all these conditions are considered, the maximum d D1s Deviation of a single outside diameter of the outer
The static equivalent load is a hypothetical load that produces
Reliability (%) 90 95 96 97 98 99 permissible speed may be higher than the limiting speed ring flange
a contact stress equal to the above maximum stress under
found in the bearing table. It is recommended that NSK be
actual conditions, while the bearing is stationary (including
a1 1.00 0.62 0.53 0.44 0.33 0.21 consulted regarding high-speed applications. B Inner ring width, nominal
very slow rotation or oscillation), in the area of contact
between the most heavily stressed rolling element and d Bs Deviation of a single inner ring width
The life correction factor for material, a2, is greater than one bearing raceway. The greater of the two values calculated VBs Inner ring widht variation
because of improvements in bearing steel. NSK now uses from the following equations should be adopted as the static
vacuum degassed bearing steel, and the results of tests by equivalent load on radial bearings. C Outer ring width, nominal
NSK show that life is greatly improved when compared with d Cs Deviation of a single outer ring width
earlier materials. The basic load ratings, Cr, listed in the Po = Xo Fr + Yo Fa ................................. (4.8) VCs Outer ring width variation
bearing tables were calculated considering the extended life Po = Fr ............................................. (4.9)
achieved by improvements in materials and manufacturing C1 Outer ring flange width, nominal
techniques. Consequently, when estimating life using where Po : Static equivalent load (N), {kgf} d C1s Deviation of a single outer ring flange width
Equation (4.7), it is sufficient to assume a2=1. Fr : Radial load (N), {kgf} VD1s Outer ring flange width variation
The life correction factor for operating conditions, a3, is used Fa : Axial load (N), {kgf}
to correct for various factors, particularly lubrication. If there is Xo : Static radial load factor (0.6) Kia Radial runout of assembled brg. inner ring
no misalignment between the inner and outer rings and the Yo : Static axial load factor (0.5) Kea Radial runout of assembled brg. outer ring
thickness of the lubricating film in the contact zones of the Sd Inner ring reference face (backface, where
bearing is sufficient, it is possible for a3 to be greater than The permissible static equivalent load of a bearings varies applicable) runout with bore
one; however, a3 is less than one in the following cases: depending on its basic static load rating and also their Sia Assembled brg. inner ring face (backface) runout
• When the viscosity of the lubricant in the contact zones application and operating conditions. The permissible static with raceway
between the raceways and rolling elements is low. load factor, fs, is a safety factor that is applied to the basic SD Variation of brg. outside surface generatrix inclination
• When the circumferential speed of the rolling elements is static load rating. It is defined by the ratio in Equation (4.10). with outer ring reference face (backface)
very slow. The generally recommended values of fs are listed in Table Sea Assembled brg. outer ring face (backface) runout
• When the bearing temperature is high. 4.3. with raceway
• When the lubricant is contaminated by water or foreign Sea1 Assembled brg. outer ring flange back face runout
matter. Co............................................. with raceway
fs = (4.10)
Po
• When misalignment of the inner and outer rings is
excessive. where Co : Basic static load rating (N), {kgf}
Po : Static equivalent load (N), {kgf}
It is difficult to determine the proper value for a3 for specific
operating conditions because there are still many unknowns. Table 4.3 Values of permissible static load factor fs
Since the material factor a2 is also influenced by the
operating conditions, there is a proposal to combine a2 and Operating conditions
Lower limit of fs
a3 into one quantity (a2
a3), and not conider them of ball bearings
independently. In this case, under normal lubricating and Low-noise applications 2
operating conditions, the product (a2
a3) should be assumed
equal to one. However, if the viscosity of the lubricant is too Bearings subjected to vibration and
1.5
low, the value drops to as low as 0.2. If there is no shock loads
misalignment and a lubricant with high viscosity is used so Standard operating conditions 1
sufficient fluid-film thickness is secured, the product of (a2
a3)
can be set around two.

16 17
Bearing tolerances

(2) Flange width tolerances and running accuracies related to flange Units: pm
Variation of brg outside surface Flange backface runout
Nominal bearing Deviation of flange width Variation of flange width d Cls generatrix inclination with raceway
outside diameter d Cls with flange backface
D (mm) VCls SD1 Seal
Normal and Classes 6, 5, 4, 2 Normal and Class 6 Class 5 Class 4 Class 2 Class 5 Class 4 Class 2 Class 5 Class 4 Class 2
over incl. high low max. max. max.
2.5( 1) 6 Use the VBs 5 2.5 1.5 8 4 1.5 11 7 3
6 18 Use the d Bs tolerance for d of the tolerance for d of
5 2.5 1.5 8 4 1.5 11 7 3
same bearing of the same class the same bearing
18 30 of the same class 5 2.5 1.5 8 4 1.5 11 7 3

Note ( 1 ) 2.5 mm is included.

Table 6.4 Tolerances and tolerance limits for inner rings and widths of outer rings (ANSI/ABMA Standard • Instrument
ball bearings • inch design) Units: pm
d dmp d ds Vdp Vdmp d Bs (or d Cs) VBs Kia Sia Sd
Nominal bore
Single brgs Combined brgs( 1)
diameter
d CLASS 5P CLASS 5P CLASS 5P CLASS 5P CLASS 5P CLASS 5P
CLASS 9P CLASS 9P CLASS 9P CLASS 9P CLASS 5P CLASS 7P CLASS 9P CLASS 5P CLASS 7P CLASS 9P CLASS 5P CLASS 7P CLASS 9P CLASS 5P CLASS 7P CLASS 9P
(mm) CLASS 7P CLASS 7P CLASS 7P CLASS 7P CLASS 7P CLASS 7P
CLASS 9P CLASS 9P
over incl. high low high low high low high low max. max. max. max. high low high low max. max. max. max. max. max. max. max. max. max. max. max.
— 10 0 – 5.1 0 – 2.5 0 – 5.1 0 – 2.5 2.5 1.3 2.5 1.3 0 – 25.4 0 – 400 5.1 2.5 1.3 3.8 2.5 1.3 7.6 2.5 1.3 7.6 2.5 1.3
10 18 0 – 5.1 0 – 2.5 0 – 5.1 0 – 2.5 2.5 1.3 2.5 1.3 0 – 25.4 0 – 400 5.1 2.5 1.3 3.8 2.5 1.3 7.6 2.5 1.3 7.6 2.5 1.3
18 30 0 – 5.1 0 – 2.5 0 – 5.1 0 – 2.5 2.5 1.3 2.5 1.3 0 – 25.4 0 – 400 5.1 2.5 1.3 3.8 2.5 2.5 7.6 3.8 1.3 7.6 3.8 1.3

Note ( ) Applicable to bearings for which the axial clearance (preload) is to be adjusted by combining two selected bearings.
1

Remarks CLASSES 5P, 7P and 9P are for precision bearings for instruments.
For the tolerances of Metric Design Pecision Bearings for instruments, it is advisable to consult NSK.

Table 6.5 Tolerances and tolerance limits for outer rings (ANSI/ABMA Standard • Instrument ball bearings • inch design) Units: pm

d Dmp d Ds VDp VDmp VCs( 1) SD Kea Sea d Dls d Cls Seal( 2)

Nominal
outside CLASS 5P CLASS 5P CLASS 5P
CLASS 9P CLASS 9P CLASS 9P Flanged outer ring
diameter CLASS 5P CLASS 7P CLASS 7P CLASS 7P
D CLASS 9P CLASS 5P CLASS 7P CLASS 9P CLASS 5P CLASS 7P CLASS 9P CLASS 5P CLASS 7P CLASS 9P CLASS 5P CLASS 7P CLASS 9P
CLASS 7P Shielded Shielded Shielded CLASS 5P CLASS 5P CLASS 5P
(mm) Open Open Open Open Open Open
sealed sealed sealed CLASS 7P CLASS 7P CLASS 7P
over incl. high low high low high low high low high low max. max. max. max. max. max. max. max. max. max. max. max. max. max. max. max. max. max. high low high low max.
— 18 0 – 5.1 0 – 2.5 0 – 5.1 +1 – 6.1 0 – 2.5 2.5 5.1 1.3 2.5 5.1 1.3 5.1 2.5 1.3 7.6 3.8 1.3 5.1 3.8 1.3 7.6 5.1 1.3 0 – 25.4 0 – 50.8 7.6
18 30 0 – 5.1 0 – 3.8 0 – 5.1 +1 – 6.1 0 – 3.8 2.5 5.1 2 2.5 5.1 2 5.1 2.5 1.3 7.6 3.8 1.3 5.1 3.8 2.5 7.6 5.1 2.5 0 – 25.4 0 – 50.8 7.6
30 50 0 – 5.1 0 – 3.8 0 – 5.1 +1 – 6.1 0 – 3.8 2.5 5.1 2 2.5 5.1 2 5.1 2.5 1.3 7.6 3.8 1.3 5.1 5.1 2.5 7.6 5.1 2.5 0 – 25.4 0 – 50.8 7.6

Notes ( ) Applicable to flange width variation for flanged bearings, but excluding CLASS 9P.
1

( 2 ) Applicable to flange back face.

Table 6.6 Guide for selection of bearing accuracy

Bearing tolerance classes
Application
ISO ANSI/ABMA
Micro motors, stepping motors, fan motors, VCR pinch Normal ABEC 1
rollers, computer printers, copy machine-feed rollers Class 6 ABEC 3
High precision motors, hard disk drive motors, dental
Class 5 CLASS 5P
spindles, servo motors, encoders, VCR drum spindles,
Class 4 CLASS 7P
VCR capstan motors, polygonal mirror scanner motors
High frequency spindles, gyro rotors, gyro gimbals Class 4 CLASS 7P, CLASS 9P

20 21
 7. Fits and internal clearances
7.1 Shaft and housing fits
The fitting practice used for bearings is extremely important generally used for miniature bearings and instrument ball When a spring is used to apply a preload to a bearing, the Tables 7.1 and 7.2 show the recommended fittings for
in achieving their expected performance. Since miniature bearings in order to simplify their mounting, prevent damage fitting of the bearing ring in contact with the spring should be various design conditions and applications.
bearings are usually used under light loads, the range during mounting and avoid changing the contact angle or loosely fitted so the ring slides smoothly. When housings are Tables 7.3 and 7.4 show allowable tolerances for shafts and
between a push fit (light interference) and a slip fit (slightly preload. This is because the occurrence of creep in miniature built of lightweight alloys, the fitting clearance of the outer housing bores for various size ranges of miniature ball
loose) is generally used. bearings is easily prevented by tightening the side face of the ring will increase with increasing temperature and possibly bearings.
In the case of a rotating inner ring, ordinary ball bearings are inner ring against a shoulder on the shaft with a nut. impair the machine's operation and reduce the bearing life;
fitted to the shaft with interference, however, a slip fit is therefore, the bearings should be mounted in a steel
bushing.

Table 7.1 Inner ring fit with shaft Table 7.2 Outer ring fit with housing

Bearing Shaft finish Suggested Bearing Housing finish Suggested

Condition Application Fit Condition Application Fit
tolerance class (p m) average fit( 1 ) tolerance class (pm) average fit( 1 )

Synchros Synchros
Class 5 Class 5
Servos Servos
Class 4 Slightly loose fit –2 Class 4 +3
Low speed Potentiometers d– 2L Low speed Potentiometers Slightly loose fit D– 2L
CLASS 5P (slip fit) 7 CLASS 5P 2
Resolvers Resolvers
CLASS 7P CLASS 7P
Gyro gimbals Gyro gimbals

Normal Small motors

Low and
Fans Class 6 Electric tools Normal
medium Transition fit d h5 ±0 Loose fit D H6 9L
Small motors ABEC 1 Vacuum cleaners ABEC 1
speeds
ABEC 3 Fan motors

Rotating
Slightly –5 inner ring +3
Computer disk spindles Class 5 d– 4L Computer disk spindles Class 5 Loose fit( 2 ) D 4L
Inner ring loose fit( 2 ) 8 0
axially Class 4 Medium Class 4
free CLASS 5P and high CLASS 5P
Rotating Video cassette recorder CLASS 7P –1 Video cassette recorder CLASS 7P –2
Close-sliding fit d– 1L speeds Slightly loose fit D– 2TL
inner ring drum spindles 6 drum spindles 5

Gyro rotors Slight Gyro rotors +5

Class 4 Class 5 Loose fit D 5L
Dental spindles interference fit d ±2.5 2T High frequency spindles 0
Medium CLASS 7P Class 4
High-frequency spindles (push fit)
and high CLASS 5P
speeds Polygonal mirror scanner CLASS 7P +3
Loose fit( 2 ) D 4L
Vacuum cleaners Normal Light motors 0
d js5 5T
Electric tools ABEC 1 interference fit
Class 5
Polygonal mirror scanner –1 Tape guide rolls Class 4 +3
Close-sliding fit d– 1L Slightly Loose fit D– 2L
motors Class 5 6 Pinch rolls CLASS 5P 2
Class 4 CLASS 7P
CLASS 5P Rotating Low to
Inner ring CLASS 7P – 5 outer ring high speeds
Gyro rotors Loose fit d– 5L
axially fixed 10 Normal
Cam followers
Class 6
Tension pulleys Interference fit D M5 5T
ABEC 1
Normal Idler gears
ABEC 3
Clutches Class 6
Inner ring Loose fit d g5 5L
Small fans ABEC 1
axially free Notes ( 1 ) L: Loose fit, T: Interference fit
ABEC 3
Rotating Low to ( 2 ) After mounting, usually bonded
outer ring high speeds
Class 5
Inner ring
Tape guide rolls Class 4 – 5
axially Loose fit d– 5L
Pinch rolls CLASS 5P 10
fixed
CLASS 7P

Notes ( 1 ) L: Loose fit, T: Interference fit

( 2 ) After mounting, usually bonded

22 23
Fits and internal clearances

Table 7.3 Tolerances for shaft diameters Units: pm 7.2 Bearing internal clearances
Shaft dia. (mm) Tolerance class for shafts The internal clearance of ball bearings greatly influences their slightly lager than the theoretical internal clearance by the
over incl. g4 g5 h4 h5 js4 js5 performance, including fatigue life, vibration, noise, heat amount of elastic deformation caused by the measuring load.
generation, etc. Consequently, it is necessary to select the The theoretical internal clearance may thus be obtained by
3 –2 to – 5 –2 to – 6 0 to –3 0 to –4 ±1.5 ±2 proper clearance considering the bearing fit, load, speed correcting the measured clearance by the amount of elastic
3 6 –4 to – 8 –4 to – 9 0 to –4 0 to –5 ±2 ±2.5 and operating temperature. deformation (refer to Table 7.6 Remark #2).
NSK provides clearances in six steps as shown in Table 7.6. Table 7.7 shows the criteria for selecting the radial clearance
6 10 –5 to – 9 –5 to –11 0 to –4 0 to –6 ±2 ±3
To obatin accurate measurements, the clearance is generally for extra small and miniature ball bearings.
10 18 –6 to –10 –6 to –14 0 to –5 0 to –8 ±2.5 ±4 measured by applying a specified measuring load on the
bearing. As a result, the measured clearance is always

Table 7.4 Tolerances for housing bores Units: pm Table 7.6 Radial internal clearances in extra small
Bore dia. (mm) Tolerance class for housings and miniature ball bearings Units: pm
over incl. H5 H6 JS5 JS6 K5 K6 M5 M6 Clearance
MC1 MC2 MC3 MC4 MC5 MC6
3 +4 to 0 + 6 to 0 ±2 ±3 0 to –4 0 to – 6 –2 to – 6 –2 to – 8 symbol

3 6 +5 to 0 + 8 to 0 ±2.5 ±4 0 to –5 +2 to – 6 –3 to – 8 –1 to – 9 min. max. min. max. min. max. min. max. min. max. min. max.
6 10 +6 to 0 + 9 to 0 ±3 ±4.5 +1 to –5 +2 to – 7 –4 to –10 –3 to –12 Clearance
0 5 3 8 5 10 8 13 13 20 20 28
10 18 +8 to 0 +11 to 0 ±4 ±5.5 +2 to –6 +2 to – 9 –4 to –12 –4 to –15
18 30 +9 to 0 +13 to 0 ±4.5 ±6.5 +1 to –8 +2 to –11 –5 to –14 –4 to –17 Remarks 1. The standard clearance is MC3.
2. To obtain the measured value, add the correction amount in the table below.

Units: pm
If the accuracy of a shaft or housing does not meet the Table 7.5 Accuracy and roughness of shaft and
specification, the performance of the bearings will be affeced Clearance
and they will not perform to their full capability. For example, housing MC1 MC2 MC3 MC4 MC5 MC6
symbol
inaccuracy in the squareness of the shaft shoulder may cause Item Class of bearings Shaft Housing bore
misalignment of the bearing inner and outer rings, which may
Clearance
reduce the bearing fatigue life by adding an edge load in IT3 to IT4 IT4 to IT5 correction for 1 1 1 1 2 2
addition to the normal load. Cage fracture and seizure Tolerance for Normal, Class 6 2 2 2 2 measuring load
sometimes occur for this same reason. out-of-roundness Class 5, Class 4 IT3 to IT4 IT2 to IT3
For normal operating conditions, a truned finish or smooth 2 2 2 2
The measuring loads are as follows:
bored finish is sufficient for the fitting surface; however, a For miniature ball bearings 2.5 N {0.25 kg}
ground finish is necessary for applications where vibration and IT3 to IT4 IT4 to IT5
2 2 2 2 For extra small ball bearings 4.4 N {0.45 kgf}
noise must be low. The accuracy and surface finish of shafts Tolerance for Normal, Class 6
and housings for normal operating conditions are listed in cylindricality Class 5, Class 4 IT2 to IT3 IT2 to IT3
2 2 2 2
Table 7.5.
Table 7.7 Selection of radial clearances
Tolerance for Normal, Class 6 IT3 IT3 to IT4
shoulder runout Class 5, Class 4 IT3 IT3 Clearance
Typical application Requirement Remarks
symbol
Roughness of
fitting surfaces — 0.8 1.6 •Small bearing clearance is
Ra Shafts for precision gears, servo-mechanisms,
required with no preload. MC1
stepping motors, VCR capstan motors, other Avoid interference fits.
•Low torque is not important. MC2
low-speed applications
Remarks This table is for general recommendation using the radius •High axial rigidity is not required.
measuring method. The basic tolerance (IT) class should
be selected in accordance with the bearing precision
class. For the IT values, please refer to Appendix Table 8 Synchros, gyro gimbal radial bearings, •Low torque is required.
(Page 62). VCR drum spindles, computer disk spindles, •Axial load and rigidity are MC3 Avoid interference fits in most
polygonal mirror scanner motors, other low or normal. MC4 applications.
medium-speed applications

Gyro rotors, gyro gimbal thrust bearings, fan •Extremely low torque is •Either axial clearance is
motors, vacuum cleaners, other high-speed required. made adjustable or a spring
MC5
and high-temperature applications •High endurance and high axial preload is used.
MC6
rigidity are required. •Interference fit may be
allowed.

24 25
27
 resistance and its hardness does not decrease at high
9. Bearing materials temperature. Therefore, it is used in applications where
corrosive elements exist or where operating temperatures are
The bearing rings and rolling elements of rolling bearings are unusually high.
repeatedly subjected to high pressure with a small amount of NSK uses vacuum degassed bearing steel designated by
sliding. The materials used for the rings and rolling elements Japanese Industrial Standard (JIS) as SUJ2 (equivalent to
must there fore have the following characteristics: ASTM A 295 52100). Its stainless steel is JIS SUS440C
(equivalent to SAE J 405 51440C) produced using the Electro
•High rolling contact fatigue strength Slag Remelting Method (ESR).
•High hardness NSK selects bearing steels containing a minimum of oxygen,
•High wear resistance hydrogen, nitrogen, and hydrogen-compound impurities.
•High dimensional stability The rolling fatigue life of bearings has been remarkably
•High mechanicalstrength improved using these materials combined with the
appropriate heat treatment.
Other characteristics, such as ease of production, shock and Regarding stainless steel bearings with reduced noise, please
heat resistance, and corrosion resistance, are required consult NSK.
depending on individual applications.
The material used for the rings and balls in miniature ball
bearings is either bearing steel or martensitic stainless steel.
The chemical composition of each is shown in Table 9.1.
Bearing steel provides a longer fatigue life because of its high
hardness, and it is also superior with respect to running noise
and torque. Stainless steel has good corrosion

Bearing Tables
Table 9.1 Chemical composition of high-carbon chromium bearing steel and stainless steel
Chemical composition (%)
Standard Symbol
C Si Mn P S Cr Mo

JIS G 4805 SUJ2 0.95 to 1.10 0.15 to 0.35 Less than 0.50 Less than 0.025 Less than 0.025 1.30 to 1.60

ASTM A 295 52100 0.93 to 1.05 0.15 to 0.35 0.25 to 0.45 Less than 0.025 Less than 0.015 1.30 to 1.60 Less than 0.10

JIS G 4303 SUS 440C 0.95 to 1.20 Less than 1.00 Less than 1.00 Less than 0.040 Less than 0.030 16.00 to 18.00 Less than 0.75

SAE J 405 51440C 0.95 to 1.20 Less than 1.00 Less than 1.00 Less than 0.040 Less than 0.030 16.00 to 18.00 Less than 0.75

28 29
Bearing Tables
CONTENTS

Deep groove ball bearings Page

Single-row deep groove ball bearings ........................................... 32 – 37
Metric series Bore diameter 1 – 9 mm ................................. 32 – 35
Inch series Bore diameter 1.016 – 9.525 mm ................... 36 – 37
Deep groove ball bearings with flanged outer ring ......................... 38 – 43
Metric series Bore diameter 1 – 9 mm ................................. 38 – 41
Inch series Bore diameter 1.191 – 9.525 mm ................... 42 – 43
Deep groove ball bearings with extended inner ring ...................... 44 – 45
Inch series Bore diameter 1.191 – 7.938 mm
Deep groove ball bearings with extended inner ring, flanged ......... 46 – 47
Inch series Bore diameter 1.191 – 7.938 mm
Ball bearings for synchros ............................................................. 48 – 49
Inch series Bore diameter 1.984 – 6.350 mm
Extra-thin-section deep groove ball bearings ................................ 50 – 51
Metric series Bore diameter 10 – 15 mm
Angular contact ball bearings
Metric series Bore diameter 4 – 9 mm ................................. 50 – 51

31
Single-row deep groove ball bearings
Metric series
600, MR
B B1 B1 B1
Bore diameter r r1
r1 ra rb
r1
5 – 9 mm r1 r1 ra
r r1 rb
D d D d D d D d Da da Db db

Open type Shielded type Non-contact Contact sealed type

ZZ · ZZ1 sealed type DD
VV

Boundary dimensions Basic load ratings Limiting speeds (min-1) Bearing numbers Abutment and fillet dimensions Mass Basic
(mm) (N) {kgf} Grease Oil (mm) (g) bearing
(2)
Open Open numbers Actual size
(1) (1)
d D B B1 r r1 Cr Cor Cr Cor Z·ZZ D·DD Z Open Shielded Seales da db Da Db ra rb Open Shielded
min. min. V·W min. max. max. min. max. max. approx.
5 8 2 — 0.1 — 310 120 31 12 53 000 — 63 000 MR 85 — — — 5.8 — 7.2 — 0.1 — 0.26 — MR 85
8 — 2.5 — 0.1 278 131 28 13 53 000 — 63 000 — MR 85 ZZ — — — 5.8 — 7.4 — 0.1 — 0.34 MR 85
9 2.5 3 0.15 0.15 430 168 44 17 50 000 — 60 000 MR 95 MR 95 ZZ1 — — 6.2 6.0 7.8 8.2 0.15 0.15 0.50 0.58 MR 95
10 3 4 0.15 0.15 430 168 44 17 50 000 — 60 000 MR 105 MR 105 ZZ — — 6.2 6.0 8.8 8.4 0.15 0.15 0.95 1.29 MR 105
11 — 4 — 0.15 715 276 73 28 48 000 — 56 000 — MR 115 ZZ VV — — 6.3 — 9.8 — 0.15 — 1.5 MR 115

11 3 5 0.15 0.15 715 281 73 29 45 000 — 53 000 685 685 ZZ — — 6.2 6.2 9.8 9.9 0.15 0.15 1.2 1.96 685
13 4 4 0.2 0.2 1 080 430 110 44 43 000 40 000 50 000 695 695 ZZ1 VV DD 6.6 6.6 11.4 11.2 0.2 0.2 2.45 2.5 695
14 5 5 0.2 0.2 1 330 505 135 52 40 000 38 000 50 000 605 605 ZZ — DD 6.6 6.9 12.4 12.2 0.2 0.2 3.54 3.48 605

16 5 5 0.3 0.3 1 730 670 177 68 36 000 32 000 43 000 625 625 ZZ1 VV DD 7.0 7.5 14.0 13.8 0.3 0.3 4.95 4.86 625
19 6 6 0.3 0.3 2 340 885 238 90 32 000 30 000 40 000 635 635 ZZ1 VV DD 7.0 8.5 17.0 16.5 0.3 0.3 8.56 8.34 635

6 10 2.5 3 0.15 0.1 495 218 51 22 45 000 — 53 000 MR 106 MR 106 ZZ1 — — 7.2 7.0 8.8 9.3 0.15 0.1 0.56 0.68 MR 106
12 3 4 0.2 0.15 715 292 73 30 43 000 40 000 50 000 MR 126 MR 126 ZZ — DD 7.6 7.2 10.4 10.9 0.2 0.15 1.27 1.74 MR 126
13 3.5 5 0.15 0.15 1 080 440 110 45 40 000 38 000 50 000 686 A 686 A ZZ VV DD 7.2 7.4 11.8 11.7 0.15 0.15 1.91 2.69 686 A

15 5 5 0.2 0.2 1 730 670 177 68 40 000 36 000 45 000 696 696 ZZ1 VV DD 7.6 7.9 13.4 13.3 0.2 0.2 3.88 3.72 696
17 6 6 0.3 0.3 2 260 835 231 85 38 000 34 000 45 000 606 606 ZZ VV DD 8.0 8.2 15.0 14.8 0.3 0.3 5.97 6.08 606
19 6 6 0.3 0.3 2 340 885 238 90 32 000 30 000 40 000 626 626 ZZ1 VV DD 8.0 8.5 17.0 16.5 0.3 0.3 8.15 7.94 626
22 7 7 0.3 0.3 3 300 1 370 335 140 30 000 28 000 36 000 636 636 ZZ VV DD 8.0 10.5 20.0 19.0 0.3 0.3 14 14 636

7 11 2.5 3 0.15 0.1 455 201 47 21 43 000 — 50 000 MR 117 MR 117 ZZ — — 8.2 8.0 9.8 10.5 0.15 0.1 0.62 0.72 MR 117
13 3 4 0.2 0.15 540 276 55 28 40 000 — 48 000 MR 137 MR 137 ZZ — — 8.6 9.0 11.4 11.6 0.2 0.15 1.58 2.02 MR 137
14 3.5 5 0.15 0.15 1 170 510 120 52 40 000 34 000 45 000 687 687 ZZ1 VV DD 8.2 8.5 12.8 12.7 0.15 0.15 2.13 2.97 687

17 5 5 0.3 0.3 1 610 710 164 73 36 000 28 000 43 000 697 697 ZZ1 VV DD 9.0 10.2 15.0 14.8 0.3 0.3 5.26 5.12 697
19 6 6 0.3 0.3 2 340 885 238 90 36 000 32 000 43 000 607 607 ZZ1 VV DD 9.0 9.1 17.0 16.5 0.3 0.3 7.67 7.51 607
22 7 7 0.3 0.3 3 300 1 370 335 140 30 000 28 000 36 000 627 627 ZZ VV DD 9.0 10.5 20.0 19.0 0.3 0.3 12.7 12.9 627
26 9 9 0.3 0.3 4 550 1 970 465 201 28 000 22 000 34 000 637 637 ZZ1 VV DD 9.0 12.8 24.0 22.8 0.3 0.3 24 25 637

8 12 2.5 3.5 0.15 0.1 545 274 56 28 40 000 — 48 000 MR 128 MR 128 ZZ1 — — 9.2 9.0 10.8 11.3 0.15 0.1 0.71 0.97 MR 128
14 3.5 4 0.2 0.15 820 385 83 39 38 000 32 000 45 000 MR 148 MR 148 ZZ VV DD 9.6 9.2 12.4 12.8 0.2 0.15 1.86 2.16 MR 148
16 4 5 0.2 0.2 1 610 710 164 73 36 000 28 000 43 000 688 A 688 A ZZ1 VV DD 9.6 10.2 14.4 14.2 0.2 0.2 3.12 4.02 688 A

19 6 6 0.3 0.3 2 240 910 228 93 36 000 28 000 43 000 698 698 ZZ VV DD 10.0 10.0 17.0 16.5 0.3 0.3 7.23 7.18 698
22 7 7 0.3 0.3 3 300 1 370 335 140 34 000 28 000 40 000 608 608 ZZ VV DD 10.0 10.5 20.0 19.0 0.3 0.3 12.1 12.2 608
24 8 8 0.3 0.3 3 350 1 430 340 146 28 000 24 000 34 000 628 628 ZZ VV DD 10.0 12.0 22.0 20.5 0.3 0.3 17.2 17.4 628
28 9 9 0.3 0.3 4 550 1 970 465 201 28 000 22 000 34 000 638 638 ZZ1 VV DD 10.0 12.8 26.0 22.8 0.3 0.3 28.3 28.6 638

9 17 4 5 0.2 0.2 1 330 665 136 68 36 000 24 000 43 000 689 689 ZZ1 VV DD 10.6 11.5 15.4 15.2 0.2 0.2 3.53 4.43 689
20 6 6 0.3 0.3 1 720 840 175 86 34 000 24 000 40 000 699 699 ZZ1 VV DD 11.0 12.0 18.0 17.2 0.3 0.3 8.45 8.33 699
24 7 7 0.3 0.3 3 350 1 430 340 146 32 000 24 000 38 000 609 609 ZZ VV DD 11.0 12.0 22.8 20.5 0.3 0.3 14.5 14.7 609

26 8 8 (0.6) (0.6) 4 550 1 970 465 201 28 000 22 000 34 000 629 629 ZZ VV DD 11.0 12.8 24.0 22.8 0.3 0.3 19.5 19.3 629
30 10 10 0.6 0.6 5 100 2 390 520 244 24 000 — 30 000 639 639 ZZ VV — 13.0 16.1 26.0 25.6 0.6 0.6 36.5 36 639

Notes (1) The values in parentheses are not based on ISO 15.
(2) Actual dimensions of bore and outside diameter only.
Remarks 1. When using bearings with a rotating outer ring, please contact NSK if they are sealed or shielded.
2. Bearings with double shields (ZZ, ZZ1) are also available with single shields (Z, Z1).
3. Bearings with snap rings are also available, please contact NSK.

34 35
Single-row deep groove ball bearings
Inch series
R
B B1
Bore diameter r ra ra
r
1.016 – 9.525 mm r
r ra ra
D d D d Da da Db db

Open type Shielded type

ZZ · ZZS

Boundary dimensions Basic load ratings Limiting speeds (min-1) Bearing numbers Abutment and fillet dimensions Mass Basic
(mm/inch) (N) {kgf} (mm) (g) bearing (1)
Grease Oil numbers Actual size
d D B B1 r Cr Cor Cr Cor Open Open Open Shielded da db Da Db ra Open Shielded
min. Z·ZZ Z min. max. max. min. max. approx.
1.016 0.0400 3.175 0.1250 1.191 0.0469 — — 0.1 80 23 8 2.5 130 000 150 000 R 09 — 1.9 — 2.3 — 0.1 0.04 — R 09

1.191 0.0469 3.967 0.1562 1.588 0.0625 2.380 0.0937 0.1 138 35 14 3.5 110 000 130 000 R0 R 0 ZZ 2.0 1.9 3.1 3.5 0.1 0.09 0.11 R0

1.397 0.0550 4.762 0.1875 1.984 0.0781 2.779 0.1094 0.1 231 66 24 6.5 90 000 110 000 R1 R 1 ZZ 2.2 2.3 3.9 4.1 0.1 0.15 0.19 R1

1.984 0.0781 6.350 0.2500 2.380 0.0937 3.571 0.1406 0.1 310 108 32 11 67 000 80 000 R 1-4 R 1-4 ZZ 2.8 3.9 5.5 5.9 0.1 0.35 0.50 R 1-4

2.380 0.0937 4.762 0.1875 1.588 0.0625 — — 0.1 188 60 19 6 80 000 95 000 R 133 — 3.2 — 3.9 — 0.1 0.10 R 133
4.762 0.1875 — — 2.380 0.0937 0.1 143 52 15 5.5 80 000 95 000 — R 133 ZZS — 3.0 — 4.2 0.1 0.13 R 133
7.938 0.3125 2.779 0.1094 3.571 0.1406 0.15 550 175 56 18 60 000 71 000 R 1-5 R 1-5 ZZ 3.6 4.1 6.7 7.0 0.15 0.60 0.72 R 1-5

3.175 0.1250 6.350 0.2500 2.380 0.0937 2.779 0.1094 0.1 283 95 29 9.5 67 000 80 000 R 144 R 144 ZZ 4.0 3.9 5.5 5.9 0.1 0.25 0.27 R 144
7.938 0.3125 2.779 0.1094 3.571 0.1406 0.1 560 179 57 18 60 000 67 000 R 2-5 R 2-5 ZZ 4.0 4.3 7.1 7.3 0.1 0.55 0.72 R 2-5
9.525 0.3750 2.779 0.1094 3.571 0.1406 0.15 640 225 65 23 53 000 63 000 R 2-6 R 2-6 ZZS 4.4 4.6 8.3 8.2 0.15 0.96 1.13 R 2-6

9.525 0.3750 3.967 0.1562 3.967 0.1562 0.3 630 218 64 22 56 000 67 000 R2 R 2 ZZ 5.2 4.8 7.5 8.0 0.3 1.36 1.39 R2
12.700 0.5000 4.366 0.1719 4.366 0.1719 0.3 640 225 65 23 53 000 63 000 R2A R 2 A ZZ 5.2 4.6 10.7 8.2 0.3 3.3 3.23 R2A

3.967 0.1562 7.938 0.3125 2.779 0.1094 3.175 0.1250 0.1 360 149 37 15 53 000 63 000 R 155 R 155 ZZS 4.8 5.5 7.1 7.3 0.1 0.51 0.56 R 155

4.762 0.1875 7.938 0.3125 2.779 0.1094 3.175 0.1250 0.1 360 149 37 15 53 000 63 000 R 156 R 156 ZZS 5.6 5.5 7.1 7.3 0.1 0.39 0.42 R 156
9.525 0.3750 3.175 0.1250 3.175 0.1250 0.1 710 270 73 28 50 000 60 000 R 166 R 166 ZZ 5.6 5.9 8.7 8.8 0.1 0.81 0.85 R 166
12.700 0.5000 3.967 0.1562 4.978 0.1960 0.3 1 300 485 133 49 43 000 53 000 R3 R 3 ZZ 6.8 6.5 10.7 11.2 0.3 2.21 2.79 R3

6.350 0.2500 9.525 0.3750 3.175 0.1250 3.175 0.1250 0.1 420 204 43 21 48 000 56 000 R 168 B R 168 B ZZ 7.2 7.0 8.7 8.9 0.1 0.58 0.62 R 168 B
12.700 0.5000 3.175 0.1250 4.762 0.1875 0.15 1 080 440 110 45 40 000 50 000 R 188 R 188 ZZ 7.6 7.4 11.5 11.6 0.15 1.53 2.21 R 188

15.875 0.6250 4.978 0.1960 4.978 0.1960 0.3 1 610 660 164 68 38 000 45 000 R4B R 4 B ZZ 8.4 8.4 13.8 13.8 0.3 4.50 4.43 R4B
19.050 0.7500 5.558 0.2188 7.142 0.2812 0.4 2 620 1 060 267 108 36 000 43 000 R 4 AA R 4 AA ZZ 9.4 9.0 16.0 16.6 0.4 7.48 9.17 R 4 AA

7.938 0.3125 12.700 0.5000 3.967 0.1562 3.967 0.1562 0.15 540 276 55 28 40 000 48 000 R 1810 R 1810 ZZ 9.2 9.0 11.5 11.6 0.15 1.56 1.48 R 1810

9.525 0.3750 22.225 0.8750 5.558 0.2188 7.142 0.2812 0.4 3 350 1 410 340 144 32 000 38 000 R6 R 6 ZZ 12.6 11.9 19.2 20.0 0.4 9.02 11 R6

Note (1) Actual dimensions of bore and outside diameter only.

Remarks 1. When using bearings with a rotating outer ring, please contact NSK if they are shielded.
2. Bearings with double shields (ZZ, ZZS) are also available with single shields (Z, ZS).

36 37
Deep groove ball bearings
with flanged outer ring
B
Metric series C1 B1 C2
r r1
F600, MF
Bore diameter r r1 ra rb
D d D1
1 – 4 mm D d D2 da db

Open type Shielded type

ZZ · ZZ1

Boundary dimensions Basic load ratings Limiting speeds (min-1) Bearing numbers Abutment and fillet dimensions Mass Basic
(mm) (N) {kgf} (mm) (g) bearing (2)
Grease Oil numbers Actual size
(1) (1)
d D D1 D2 B B1 C1 C2 r r1 Cr Cor Cr Cor Open Open Open Shielded Sealed da db ra rb Open Shielded
min. min. Z·ZZ Z min. max. max. max. approx.
1 3 3.8 — 1 — 0.3 — 0.05 — 80 23 8 2.5 130 000 150 000 F 681 — — — 1.4 — 0.05 — 0.04 — F 681
4 5 — 1.6 — 0.5 — 0.1 — 138 35 14 3.5 100 000 120 000 F 691 — — — 1.8 — 0.1 — 0.14 — F 691

1.2 4 4.8 — 1.8 — 0.4 — 0.1 — 138 35 14 3.5 110 000 130 000 MF 41 X — — — 2.0 — 0.1 — 0.12 — MF 41 X

1.5 4 5 5 1.2 2 0.4 0.6 0.05 0.05 112 33 11 3.5 100 000 120 000 F 681 X F 681 XZZ — — 1.9 2.1 0.05 0.05 0.09 0.14 F 681 X
5 6.5 6.5 2 2.6 0.6 0.8 0.15 0.15 237 69 24 7 85 000 100 000 F 691 X F 691 XZZ — — 2.7 2.5 0.15 0.15 0.21 0.28 F 691 X
6 7.5 7.5 2.5 3 0.6 0.8 0.15 0.15 330 98 34 10 75 000 90 000 F 601 X F 601 XZZ — — 2.7 3.0 0.15 0.15 0.42 0.52 F 601 X

2 5 6.1 6.1 1.5 2.3 0.5 0.6 0.08 0.08 169 50 17 5 85 000 100 000 F 682 F 682 ZZ — — 2.6 2.7 0.08 0.08 0.16 0.22 F 682
5 6.2 6.2 2 2.5 0.6 0.6 0.1 0.1 187 58 19 6 85 000 100 000 MF 52 B MF 52 B ZZ — — 2.8 2.7 0.1 0.1 0.21 0.27 MF 52 B
6 7.5 7.5 2.3 3 0.6 0.8 0.15 0.15 330 98 34 10 75 000 90 000 F 692 F 692 ZZ — — 3.2 3.0 0.15 0.15 0.35 0.48 F 692

6 7.2 — 2.5 — 0.6 — 0.15 — 330 98 34 10 75 000 90 000 MF 62 — — — 3.2 — 0.15 — 0.36 — MF 62
7 8.2 8.2 2.5 3 0.6 0.6 0.15 0.15 385 127 39 13 63 000 75 000 MF 72 MF 72 ZZ — — 3.2 3.8 0.15 0.15 0.52 0.56 MF 72
7 8.5 8.5 2.8 3.5 0.7 0.9 0.15 0.15 385 127 39 13 63 000 75 000 F 602 F 602 ZZ — — 3.2 3.8 0.15 0.15 0.60 0.71 F 602

2.5 6 7.1 7.1 1.8 2.6 0.5 0.8 0.08 0.08 208 74 21 7.5 71 000 80 000 F 682 X F 682 XZZ — — 3.1 3.7 0.08 0.08 0.25 0.36 F 682 X
7 8.5 8.5 2.5 3.5 0.7 0.9 0.15 0.15 385 127 39 13 63 000 67 000 F 692 X F 692 XZZ — — 3.7 3.8 0.15 0.15 0.51 0.68 F 692 X
8 9.2 — 2.5 — 0.6 — 0.2 — 560 179 57 18 60 000 71 000 MF 82 X — — — 4.1 — 0.2 — 0.62 — MF 82 X
8 9.5 9.5 2.8 4 0.7 0.9 0.15 0.15 550 175 56 18 60 000 71 000 F 602 X F 602 XZZ — — 3.7 4.1 0.15 0.15 0.74 0.98 F 602 X

3 6 7.2 7.2 2 2.5 0.6 0.6 0.1 0.1 208 74 21 7.5 71 000 80 000 MF 63 MF 63 ZZ — — 3.8 3.7 0.1 0.1 0.27 0.33 MF 63
7 8.1 8.1 2 3 0.5 0.8 0.1 0.1 390 130 40 13 63 000 75 000 F 683 A F 683 A ZZ — — 3.8 4.0 0.1 0.1 0.37 0.53 F 683 A
8 9.2 — 2.5 — 0.6 — 0.15 — 560 179 57 18 60 000 67 000 MF 83 — — — 4.2 — 0.15 — 0.56 — MF 83

8 9.5 9.5 3 4 0.7 0.9 0.15 0.15 560 179 57 18 60 000 67 000 F 693 F 693 ZZ — — 4.2 4.3 0.15 0.15 0.70 0.97 F 693
9 10.2 10.6 2.5 4 0.6 0.8 0.2 0.15 570 187 58 19 56 000 67 000 MF 93 MF 93 ZZ — — 4.6 4.3 0.2 0.15 0.81 1.34 MF 93
9 10.5 10.5 3 5 0.7 1 0.15 0.15 570 187 58 19 56 000 67 000 F 603 F 603 ZZ — — 4.2 4.3 0.15 0.15 1.0 1.63 F 603
10 11.5 11.5 4 4 1 1 0.15 0.15 630 218 64 22 50 000 60 000 F 623 F 623 ZZ — — 4.2 4.3 0.15 0.15 1.85 1.86 F 623
13 15 15 5 5 1 1 0.2 0.2 1 300 485 133 49 36 000 43 000 F 633 F 633 ZZ — — 4.6 6.0 0.2 0.2 3.73 3.59 F 633

4 7 8.2 — 2 — 0.6 — 0.1 — 310 115 32 12 60 000 67 000 MF 74 — — — 4.8 — 0.1 — 0.29 — MF 74
7 — 8.2 — 2.5 — 0.6 — 0.1 255 107 26 11 60 000 71 000 — MF 74 ZZ — — — 4.8 — 0.1 — 0.35 MF 74
8 9.2 9.2 2 3 0.6 0.6 0.15 0.1 395 139 40 14 56 000 67 000 MF 84 MF 84 ZZ — — 5.2 5.0 0.15 0.1 0.44 0.63 MF 84
9 10.3 10.3 2.5 4 0.6 1 0.15 0.15 640 225 65 23 53 000 63 000 F 684 F 684 ZZ — — 4.8 5.2 0.1 0.1 0.70 1.14 F 684

10 11.2 11.6 3 4 0.6 0.8 0.2 0.15 710 270 73 28 50 000 60 000 MF 104 B MF 104 B ZZ — — 5.6 5.9 0.2 0.15 1.13 1.59 MF 104 B
11 12.5 12.5 4 4 1 1 0.15 0.15 960 345 98 35 48 000 56 000 F 694 F 694 ZZ — — 5.2 5.6 0.15 0.15 1.91 1.96 F 694
12 13.5 13.5 4 4 1 1 0.2 0.2 960 345 98 35 48 000 56 000 F 604 F 604 ZZ — — 5.6 5.6 0.2 0.2 2.53 2.53 F 604

13 15 15 5 5 1 1 0.2 0.2 1 300 485 133 49 40 000 48 000 F 624 F 624 ZZ — — 5.6 6.0 0.2 0.2 3.38 3.53 F 624
16 18 18 5 5 1 1 0.3 0.3 1 730 670 177 68 36 000 43 000 F 634 F 634 ZZ1 — — 6.0 7.5 0.3 0.3 5.73 5.65 F 634

Notes (1) The values in parentheses are not based on ISO 15.
(2) Actual dimensions of bore and outside diameter only.
Remarks 1. When using bearings with a rotating outer ring, please contact NSK if they are shielded.
2. Bearings with double shields (ZZ, ZZ1) are also available with single shields (Z, Z1).

38 39
Deep groove ball bearings
with flanged outer ring
Metric series B
C1 B1 C2 B1 C2 B1 C2
r r1 r1
F600, MF r1

Bore diameter r r1 r1 r1 ra rb

5 – 9 mm D d D1 D d D2 D d D2 D d D2 da db

Open type Shielded type Non-contact Contact sealed type

ZZ · ZZ1 sealed type DD
VV

Boundary dimensions Basic load ratings Limiting speeds (min-1) Bearing numbers Abutment and fillet dimensions Mass Basic
(mm) (N) {kgf} Grease Oil (mm) (g) bearing (1)
Open Open numbers Actual size
d D D1 D2 B B1 C1 C2 r r1 Cr Cor Cr Cor Z·ZZ D·DD Z Open Shielded Sealed da db ra rb Open Shielded
min. min. V·W min. max. max. max. approx.
5 8 9.2 — 2 — 0.6 — 0.1 — 310 120 31 12 53 000 — 63 000 MF 85 — — — 5.8 — 0.1 — 0.33 — MF 85
8 — 9.2 — 2.5 — 0.6 — 0.1 278 131 28 13 53 000 — 63 000 — MF 85 ZZ — — — 5.8 — 0.1 — 0.41 MF 85
9 10.2 10.2 2.5 3 0.6 0.6 0.15 0.15 430 168 44 17 50 000 — 60 000 MF 95 MF 95 ZZ1 — — 6.2 6.0 0.15 0.15 0.59 0.66 MF 95
10 11.2 11.6 3 4 0.6 0.8 0.15 0.15 430 168 44 17 50 000 — 60 000 MF 105 MF 105 ZZ — — 6.2 6.0 0.15 0.15 1.05 1.46 MF 105

11 12.5 12.5 3 5 0.8 1 0.15 0.15 715 281 73 29 45 000 53 000 F 685 F 685 ZZ — — 6.2 6.2 0.15 0.15 1.37 2.18 F 685
13 15 15 4 4 1 1 0.2 0.2 1 080 430 110 44 43 000 40 000 50 000 F 695 F 695 ZZ VV DD 6.6 6.6 0.2 0.2 2.79 2.84 F 695
14 16 16 5 5 1 1 0.2 0.2 1 330 505 135 52 40 000 38 000 50 000 F 605 F 605 ZZ — DD 6.6 6.9 0.2 0.2 3.9 3.85 F 605

16 18 18 5 5 1 1 0.3 0.3 1 730 670 177 68 36 000 32 000 43 000 F 625 F 625 ZZ1 VV DD 7.0 7.5 0.3 0.3 5.37 5.3 F 625
19 22 22 6 6 1.5 1.5 0.3 0.3 2 340 885 238 90 32 000 30 000 40 000 F 635 F 635 ZZ1 VV DD 7.0 8.5 0.3 0.3 9.49 9.49 F 635

6 10 11.2 11.2 2.5 3 0.6 0.6 0.15 0.1 495 218 51 22 45 000 — 53 000 MF 106 MF 106 ZZ1 — — 7.2 7.0 0.15 0.1 0.65 0.77 MF 106
12 13.2 13.6 3 4 0.6 0.8 0.2 0.15 715 292 73 30 43 000 40 000 50 000 MF 126 MF 126 ZZ — DD 7.6 7.2 0.2 0.15 1.38 1.94 MF 126
13 15 15 3.5 5 1 1.1 0.15 0.15 1 080 440 110 45 40 000 38 000 50 000 F 686 A F 686 A ZZ VV DD 7.2 7.4 0.15 0.15 2.25 3.04 F 686 A

15 17 17 5 5 1.2 1.2 0.2 0.2 1 730 670 177 68 40 000 36 000 45 000 F 696 F 696 ZZ1 VV DD 7.6 7.9 0.2 0.2 4.34 4.26 F 696
17 19 19 6 6 1.2 1.2 0.3 0.3 2 260 835 231 85 38 000 34 000 45 000 F 606 F 606 ZZ VV DD 8.0 8.2 0.3 0.3 6.58 6.61 F 606
19 22 22 6 6 1.5 1.5 0.3 0.3 2 340 885 238 90 32 000 30 000 40 000 F 626 F 626 ZZ1 VV DD 8.0 8.5 0.3 0.3 9.09 9.09 F 626
22 25 25 7 7 1.5 1.5 0.3 0.3 3 300 1 370 335 140 30 000 28 000 36 000 F 636 F 636 ZZ VV DD 8.0 10.5 0.3 0.3 14.6 14.7 F 636

7 11 12.2 12.2 2.5 3 0.6 0.6 0.15 0.1 455 201 47 21 43 000 — 50 000 MF 117 MF 117 ZZ — — 8.2 8.0 0.15 0.1 0.72 0.82 MF 117
13 14.2 14.6 3 4 0.6 0.8 0.2 0.15 540 276 55 28 40 000 — 48 000 MF 137 MF 137 ZZ — — 8.6 9.0 0.2 0.15 1.7 2.23 MF 137
14 16 16 3.5 5 1 1.1 0.15 0.15 1 170 510 120 52 40 000 34 000 45 000 F 687 F 687 ZZ1 VV DD 8.2 8.5 0.15 0.15 2.48 3.37 F 687

17 19 19 5 5 1.2 1.2 0.3 0.3 1 610 710 164 73 36 000 28 000 43 000 F 697 F 697 ZZ1 VV DD 9.0 10.2 0.3 0.3 5.65 5.65 F 697
19 22 22 6 6 1.5 1.5 0.3 0.3 2 340 885 238 90 36 000 32 000 43 000 F 607 F 607 ZZ1 VV DD 9.0 9.1 0.3 0.3 8.66 8.66 F 607
22 25 25 7 7 1.5 1.5 0.3 0.3 3 300 1 370 335 140 30 000 28 000 36 000 F 627 F 627 ZZ VV DD 9.0 10.5 0.3 0.3 14.2 14.2 F 627

8 12 13.2 13.6 2.5 3.5 0.6 0.8 0.15 0.1 545 274 56 28 40 000 — 48 000 MF 128 MF 128 ZZ1 — — 9.2 9.0 0.15 0.1 0.82 1.15 MF 128
14 15.6 15.6 3.5 4 0.8 0.8 0.2 0.15 820 385 83 39 38 000 32 000 45 000 MF 148 MF 148 ZZ VV DD 9.6 9.2 0.2 0.15 2.09 2.39 MF 148
16 18 18 4 5 1 1.1 0.2 0.2 1 610 710 164 73 36 000 30 000 43 000 F 688 A F 688 A ZZ1 VV DD 9.6 10.2 0.2 0.2 3.54 4.47 F 688 A

19 22 22 6 6 1.5 1.5 0.3 0.3 2 240 910 228 93 36 000 28 000 43 000 F 698 F 698 ZZ VV DD 10.0 10.0 0.3 0.3 8.35 8.3 F 698
22 25 25 7 7 1.5 1.5 0.3 0.3 3 300 1 370 335 140 34 000 28 000 40 000 F 608 F 608 ZZ VV DD 10.0 10.5 0.3 0.3 13.4 13.5 F 608

9 17 19 19 4 5 1 1.1 0.2 0.2 1 330 665 136 68 36 000 24 000 43 000 F 689 F 689 ZZ1 VV DD 10.6 11.5 0.2 0.2 3.97 4.91 F 689
20 23 23 6 6 1.5 1.5 0.3 0.3 1 720 840 175 86 34 000 24 000 40 000 F 699 F 699 ZZ1 VV DD 11.0 12.0 0.3 0.3 9.51 9.51 F 699

Note (1) Actual dimensions of bore and outside diameter only.

Remarks 1. When using bearings with a rotating outer ring, please contact NSK if they are shielded.
2. Bearings with double shields (ZZ, ZZ1) are also available with single shields (Z, Z1).

40 41
Deep groove ball bearings
with flanged outer ring
Inch series B
C1 B1 C2

r r
FR
Bore diameter r r ra ra

1.191 – 9.525 mm D d D1 D d D1 da db

Open type Shielded type

ZZ · ZZS

Boundary dimensions Basic load ratings Limiting speeds (min -1) Bearing numbers Abutment and fillet dimensions Mass Basic
(mm/inch) (N) {kgf} (mm) (g) bearing (1)
Grease Oil numbers Actual size
d D D1 B B1 C1 C2 r Cr Cor Cr Cor Open Open Open Shielded da db ra Open Shielded
min. Z·ZZ Z min. max. max. approx.
1.191 0.0469 3.967 0.1562 5.156 0.203 1.588 0.0625 2.380 0.0937 0.330 0.013 0.790 0.031 0.1 138 35 14 3.5 110 000 130 000 FR 0 FR 0 ZZ 2.0 1.9 0.1 0.11 0.16 FR 0

1.397 0.0550 4.762 0.1875 5.944 0.234 1.984 0.0781 2.779 0.1094 0.580 0.023 0.790 0.031 0.1 231 66 24 6.5 90 000 110 000 FR 1 FR 1 ZZ 2.2 2.3 0.1 0.20 0.25 FR 1

1.984 0.0781 6.350 0.2500 7.518 0.296 2.380 0.0937 3.571 0.1406 0.580 0.023 0.790 0.031 0.1 310 108 32 11 67 000 80 000 FR 1-4 FR 1-4 ZZ 2.8 3.9 0.1 0.41 0.58 FR 1-4

2.380 0.0937 4.762 0.1875 5.944 0.234 1.588 0.0625 — — 0.460 0.018 — — 0.1 188 60 19 6 80 000 95 000 FR 133 — 3.2 — 0.1 0.13 — FR 133
4.762 0.1875 5.944 0.234 — — 2.380 0.0937 — — 0.790 0.031 0.1 143 52 15 5.5 80 000 95 000 — FR 133 ZZS — 3.0 0.1 0.19 FR 133
7.938 0.3125 9.119 0.359 2.779 0.1094 3.571 0.1406 0.580 0.023 0.790 0.031 0.15 550 175 56 18 60 000 71 000 FR 1-5 FR 1-5 ZZ 3.6 4.1 0.15 0.68 0.82 FR 1-5

3.175 0.1250 6.350 0.2500 7.518 0.296 2.380 0.0937 2.779 0.1094 0.580 0.023 0.790 0.031 0.1 283 95 29 9.5 67 000 80 000 FR 144 FR 144 ZZ 4.0 3.9 0.1 0.31 0.35 FR 144
7.938 0.3125 9.119 0.359 2.779 0.1094 3.571 0.1406 0.580 0.023 0.790 0.031 0.1 560 179 57 18 60 000 67 000 FR 2-5 FR 2-5 ZZ 4.0 4.3 0.1 0.62 0.81 FR 2-5
9.525 0.3750 10.719 0.422 2.779 0.1094 3.571 0.1406 0.580 0.023 0.790 0.031 0.15 640 225 65 23 53 000 63 000 FR 2-6 FR 2-6 ZZS 4.4 4.6 0.15 1.04 1.25 FR 2-6
9.525 0.3750 11.176 0.440 3.967 0.1562 3.967 0.1562 0.760 0.030 0.760 0.030 0.3 630 218 64 22 56 000 67 000 FR 2 FR 2 ZZ 5.2 4.8 0.3 1.51 1.55 FR 2

3.967 0.1562 7.938 0.3125 9.119 0.359 2.779 0.1094 3.175 0.1250 0.580 0.023 0.910 0.036 0.1 360 149 37 15 53 000 63 000 FR 155 FR 155 ZZS 4.8 5.5 0.1 0.59 0.67 FR 155

4.762 0.1875 7.938 0.3125 9.119 0.359 2.779 0.1094 3.175 0.1250 0.580 0.023 0.910 0.036 0.1 360 149 37 15 53 000 63 000 FR 156 FR 156 ZZS 5.6 5.5 0.1 0.47 0.53 FR 156
9.525 0.3750 10.719 0.422 3.175 0.1250 3.175 0.1250 0.580 0.023 0.790 0.031 0.1 710 270 73 28 50 000 60 000 FR 166 FR 166 ZZ 5.6 5.9 0.1 0.90 0.98 FR 166
12.700 0.5000 14.351 0.565 4.978 0.1960 4.978 0.1960 1.070 0.042 1.070 0.042 0.3 1 300 485 133 49 43 000 53 000 FR 3 FR 3 ZZ 6.8 6.5 0.3 2.97 3.09 FR 3

6.350 0.2500 9.525 0.3750 10.719 0.422 3.175 0.1250 3.175 0.1250 0.580 0.023 0.910 0.036 0.1 420 204 43 21 48 000 56 000 FR 168 B FR 168 BZZ 7.2 7.0 0.1 0.66 0.75 FR 168 B
12.700 0.5000 13.894 0.547 3.175 0.1250 4.762 0.1875 0.580 0.023 1.140 0.045 0.15 1 080 440 110 45 40 000 50 000 FR 188 FR 188 ZZ 7.6 7.4 0.15 1.64 2.49 FR 188
15.875 0.6250 17.526 0.690 4.978 0.1960 4.978 0.1960 1.070 0.042 1.070 0.042 0.3 1 610 660 164 68 38 000 45 000 FR 4 B FR 4 BZZ 8.4 8.4 0.3 4.78 4.78 FR 4 B

7.938 0.3125 12.700 0.5000 13.894 0.547 3.967 0.1562 3.967 0.1562 0.790 0.031 0.790 0.031 0.15 540 276 55 28 40 000 48 000 FR 1810 FR 1810 ZZ 9.2 9.0 0.15 1.71 1.63 FR 1810

9.525 0.3750 22.225 0.8750 24.613 0.969 7.142 0.2812 7.142 0.2812 1.570 0.062 1.570 0.062 0.4 3 350 1 410 340 144 32 000 38 000 FR 6 FR 6 ZZ 12.6 11.9 0.4 10.1 12.1 FR 6

Note (1) Actual dimensions of bore and outside diameter only.

Remarks 1. When using bearings with a rotating outer ring, please contact NSK if they are shielded.
2. Bearings with double shields (ZZ, ZZS) are also available with single shields (Z, ZS).

42 43
Deep groove ball bearings
with extended inner ring
Inch series
C C1
RW r r
ra ra
Bore diameter r r
Da da Db db
1.016 – 9.525 mm D d D d
B B1

Open type Shielded type

ZZ · ZZS

Boundary dimensions Basic load ratings Limiting speeds (min-1) Bearing numbers Abutment and fillet dimensions Mass Basic
(mm/inch) (N) {kgf} (mm) (g) bearing (1)
Grease Oil numbers Actual size
d D B B1 C C1 r Cr Cor Cr Cor Open Open Open Shielded da db Da Db ra Open Shielded
min. Z·ZZ Z min. max. max. min. max. approx.
1.016 0.0400 3.175 0.1250 1.984 0.0781 — — 1.191 0.0469 — — 0.1 80 23 8 2.5 130 000 150 000 RW 09 — 1.9 — 2.3 — 0.1 0.05 — RW 09

1.191 0.0469 3.967 0.1562 2.380 0.0937 3.175 0.1250 1.588 0.0625 2.380 0.0937 0.1 138 35 14 3.5 110 000 130 000 RW 0 RW 0 ZZ 2.0 1.9 3.1 3.5 0.1 0.11 0.16 RW 0

1.397 0.0550 4.762 0.1875 2.779 0.1094 3.571 0.1406 1.984 0.0781 2.779 0.1094 0.1 231 66 24 6.5 90 000 110 000 RW 1 RW 1 ZZ 2.2 2.3 3.9 4.1 0.1 0.17 0.25 RW 1

1.984 0.0781 6.350 0.2500 3.175 0.1250 4.366 0.1719 2.380 0.0937 3.571 0.1406 0.1 310 108 32 11 67 000 80 000 RW 1-4 RW 1-4 ZZ 2.8 3.9 5.5 5.9 0.1 0.46 0.46 RW 1-4

2.380 0.0937 4.762 0.1875 2.380 0.0937 — — 1.588 0.0625 — — 0.1 188 60 19 6 80 000 95 000 RW 133 — 3.2 — 3.9 — 0.1 0.12 — RW 133
4.762 0.1875 — — 3.175 0.1250 — — 2.380 0.0937 0.1 143 52 15 5.5 80 000 95 000 — RW 133 ZZS — 3.0 — 4.2 0.1 0.17 RW 133
7.938 0.3125 3.571 0.1406 4.366 0.1719 2.779 0.1094 3.571 0.1406 0.15 550 175 56 18 60 000 71 000 RW 1-5 RW 1-5 ZZ 3.6 4.1 6.7 7.0 0.15 0.63 0.73 RW 1-5

3.175 0.1250 6.350 0.2500 3.175 0.1250 3.571 0.1406 2.380 0.0937 2.779 0.1094 0.1 283 95 29 9.5 67 000 80 000 RW 144 RW 144 ZZ 4.0 3.9 5.5 5.9 0.1 0.30 0.33 RW 144
7.983 0.3125 3.571 0.1406 4.366 0.1719 2.779 0.1094 3.571 0.1406 0.1 560 179 57 18 60 000 67 000 RW 2-5 RW 2-5 ZZ 4.0 4.3 7.1 7.3 0.1 0.74 0.74 RW 2-5
9.525 0.3750 3.571 0.1406 4.366 0.1719 2.779 0.1094 3.571 0.1406 0.15 640 225 65 23 53 000 63 000 RW 2-6 RW 2-6 ZZS 4.4 4.6 8.3 8.2 0.15 1.0 1.1 RW 2-6
9.525 0.3750 4.762 0.1875 4.762 0.1875 3.967 0.1562 3.967 0.1562 0.3 630 218 64 22 56 000 67 000 RW 2 RW 2 ZZ 5.2 4.8 7.5 8.0 0.3 1.4 1.3 RW 2

3.967 0.1562 7.938 0.3125 3.571 0.1406 3.967 0.1562 2.779 0.1094 3.175 0.1250 0.1 360 149 37 15 53 000 63 000 RW 155 RW 155 ZZS 4.8 5.5 7.1 7.3 0.1 0.56 0.62 RW 155

4.762 0.1875 7.938 0.3125 3.571 0.1406 3.967 0.1562 2.779 0.1094 3.175 0.1250 0.1 360 149 37 15 53 000 63 000 RW 156 RW 156 ZZS 5.6 5.5 7.1 7.3 0.1 0.44 0.49 RW 156
9.525 0.3750 3.967 0.1562 3.967 0.1562 3.175 0.1250 3.175 0.1250 0.1 710 270 73 28 50 000 60 000 RW 166 RW 166 ZZ 5.6 5.9 8.7 8.8 0.1 0.82 0.87 RW 166
12.700 0.5000 4.762 0.1875 5.771 0.2272 3.967 0.1562 4.978 0.1960 0.3 1 300 485 133 49 43 000 53 000 RW 3 RW 3 ZZ 6.8 6.5 10.7 11.2 0.3 2.33 2.90 RW 3

6.350 0.2500 9.525 0.3750 3.967 0.1562 3.967 0.1562 3.175 0.1250 3.175 0.1250 0.1 420 204 43 21 48 000 56 000 RW 168 B RW 168 BZZ 7.2 7.0 8.7 8.9 0.1 0.62 0.66 RW 168 B
12.700 0.5000 3.967 0.1562 5.558 0.2188 3.175 0.1250 4.762 0.1875 0.15 1 080 440 110 45 40 000 50 000 RW 188 RW 188 ZZ 7.6 7.4 11.5 11.6 0.15 1.7 2.1 RW 188
15.875 0.6250 5.771 0.2272 5.771 0.2272 4.978 0.1960 4.978 0.1960 0.3 1 610 660 164 68 38 000 45 000 RW 4 B RW 4 BZZ 8.4 8.4 13.8 13.8 0.3 4.72 4.62 RW 4 B

7.938 0.3125 12.700 0.5000 4.762 0.1875 4.762 0.1875 3.967 0.1562 3.967 0.1562 0.15 540 276 55 28 40 000 48 000 RW 1810 RW 1810 ZZ 9.2 9.0 11.5 11.6 0.15 1.9 1.6 RW 1810

9.525 0.3750 22.225 0.8750 7.142 0.2812 — — 5.558 0.2188 — — 0.4 3 350 1 410 340 144 32 000 38 000 RW 6 — 12.6 — 19.2 — 0.4 10 — RW 6

Note (1) Actual dimensions of bore and outside diameter only.

Remarks 1. When using bearings with a rotating outer ring, please contact NSK if they are shielded.
2. Bearings with double shields (ZZ, ZZS) are also available with single shields (Z, ZS).

44 45
Deep groove ball bearings
with extended inner ring, flanged
Inch series C C1
C2 C3
r
FRW r

Bore diameter r r
ra ra

1.191 – 7.938 mm D d D1 D d D1 da db
B B1

Open type Shielded type

ZZ · ZZS

Boundary dimensions Basic load ratings Limiting speeds (min-1) Bearing numbers Abutment and fillet dimensions Mass Basic
(mm/inch) (N) {kgf} (mm) (g) bearing (1)
Grease Oil numbers Actual size
d D D1 B B1 C C1 C2 C3 r Cr Cor Cr Cor Open Open Open Shielded da db ra Open Shielded
min. Z·ZZ Z min. max. max. approx.
1.191 0.0469 3.967 0.1562 5.156 0.203 2.380 0.0937 3.175 0.1250 1.588 0.0625 2.380 0.0937 0.330 0.013 0.790 0.031 0.1 138 35 14 3.5 110 000 130 000 FRW 0 FRW 0 ZZ 2.0 1.9 0.1 0.14 0.19 FRW 0

1.397 0.0550 4.762 0.1875 5.944 0.234 2.779 0.1094 3.571 0.1406 1.984 0.0781 2.779 0.1094 0.580 0.023 0.790 0.031 0.1 231 66 24 6.5 90 000 110 000 FRW 1 FRW 1 ZZ 2.2 2.3 0.1 0.24 0.32 FRW 1

1.984 0.0781 6.350 0.2500 7.518 0.296 3.175 0.1250 4.366 0.1719 2.380 0.0937 3.571 0.1406 0.580 0.023 0.790 0.031 0.1 310 108 32 11 67 000 80 000 FRW 1-4 FRW 1-4 ZZ 2.8 3.9 0.1 0.59 0.59 FRW 1-4

2.380 0.0937 4.762 0.1875 5.944 0.234 2.380 0.0937 — — 1.588 0.0625 — — 0.460 0.018 — 0.1 188 60 19 6 80 000 95 000 FRW 133 — 3.2 — 0.1 0.17 — FRW 133
4.762 0.1875 5.944 0.234 — — 3.175 0.1250 — — 2.380 0.0937 0.790 0.031 0.1 143 52 15 5.5 80 000 95 000 — FRW 133 ZZS — 3.0 0.1 — 0.22 FRW 133
7.938 0.3125 9.119 0.359 3.571 0.1406 4.366 0.1719 2.779 0.1094 3.571 0.1406 0.580 0.023 0.790 0.031 0.15 550 175 56 18 60 000 71 000 FRW 1-5 FRW 1-5 ZZ 3.6 4.1 0.15 0.83 0.93 FRW 1-5

3.175 0.1250 6.350 0.2500 7.518 0.296 3.175 0.1250 3.571 0.1406 2.380 0.0937 2.779 0.1094 0.580 0.023 0.790 0.031 0.1 283 95 29 9.5 67 000 80 000 FRW 144 FRW 144 ZZ 4.0 3.9 0.1 0.44 0.47 FRW 144
7.938 0.3125 9.119 0.359 3.571 0.1406 4.366 0.1719 2.779 0.1094 3.571 0.1406 0.580 0.023 0.790 0.031 0.1 560 179 57 18 60 000 67 000 FRW 2-5 FRW 2-5 ZZ 4.0 4.3 0.1 0.93 0.93 FRW 2-5
9.525 0.3750 10.719 0.422 3.571 0.1406 4.366 0.1719 2.779 0.1094 3.571 0.1406 0.580 0.023 0.790 0.031 0.15 640 225 65 23 53 000 63 000 FRW 2-6 FRW 2-6 ZZS 4.4 4.6 0.15 1.3 1.4 FRW 2-6
9.525 0.3750 11.176 0.440 4.762 0.1875 4.762 0.1875 3.967 0.1562 3.967 0.1562 0.760 0.030 0.760 0.030 0.3 630 218 64 22 56 000 67 000 FRW 2 FRW 2 ZZ 5.2 4.8 0.3 1.8 1.7 FRW 2

3.967 0.1562 7.938 0.3125 9.119 0.359 3.571 0.1406 3.967 0.1562 2.779 0.1094 3.175 0.1250 0.580 0.023 0.910 0.036 0.1 360 149 37 15 53 000 63 000 FRW 155 FRW 155 ZZS 4.8 5.5 0.1 0.73 0.79 FRW 155

4.762 0.1875 7.938 0.3125 9.119 0.359 3.571 0.1406 3.967 0.1562 2.779 0.1094 3.175 0.1250 0.580 0.023 0.910 0.036 0.1 360 149 37 15 53 000 63 000 FRW 156 FRW 156 ZZS 5.6 5.5 0.1 0.58 0.63 FRW 156
9.525 0.3750 10.719 0.422 3.967 0.1562 3.967 0.1562 3.175 0.1250 3.175 0.1250 0.580 0.023 0.790 0.031 0.1 710 270 73 28 50 000 60 000 FRW 166 FRW 166 Z 5.6 5.9 0.1 1.2 1.2 FRW 166
12.700 0.5000 14.351 0.565 4.762 0.1875 5.771 0.2272 3.967 0.1562 4.978 0.1960 1.070 0.042 1.070 0.042 0.3 1 300 485 133 49 43 000 53 000 FRW 3 FRW 3 ZZ 6.8 6.5 0.3 3.1 3.2 FRW 3

6.350 0.2500 9.525 0.3750 10.719 0.422 3.967 0.1562 3.967 0.1562 3.175 0.1250 3.175 0.1250 0.580 0.023 0.910 0.036 0.1 420 204 43 21 48 000 56 000 FRW 168 B FRW 168 BZZ 7.2 7.0 0.1 0.70 0.79 FRW 168 B
12.700 0.5000 13.894 0.547 3.967 0.1562 5.558 0.2188 3.175 0.1250 4.762 0.1875 0.580 0.023 1.140 0.045 0.15 1 080 440 110 45 40 000 50 000 FRW 188 FRW 188 ZZ 7.6 7.4 0.15 2.1 2.5 FRW 188
15.875 0.6250 17.526 0.690 5.771 0.2272 5.771 0.2272 4.978 0.1960 4.978 0.1960 1.070 0.042 1.070 0.042 0.3 1 610 660 164 68 38 000 45 000 FRW 4 B FRW 4 BZZ 8.4 8.4 0.3 5.08 4.98 FRW 4 B

7.938 0.3125 12.700 0.5000 13.894 0.547 4.762 0.1875 4.762 0.1875 3.967 0.1562 3.967 0.1562 0.790 0.031 0.790 0.031 0.15 540 276 55 28 40 000 48 000 FRW 1810 FRW 1810 ZZ 9.2 9.0 0.15 2.3 2.1 FRW 1810
1
Note ( ) Actual dimensions of bore and outside diameter only.
Remarks 1. When using bearings with a rotating outer ring, please contact NSK if they are shielded.
2. Bearings with double shields (ZZ, ZZS) are also available with single shields (Z, ZS).

46 47
Ball bearings for synchros
Inch series
SR · · X
B
Bore diameter r
B1
r
ra ra

3.175 – 4.762 mm
ra ra
r r
D d D d Da da Da db

Open type Shielded type

ZZS

Boundary dimensions Basic load ratings Limiting speeds (mi n -1) Bearing numbers Abutment and fillet dimensions Mass
(mm/inch) (N) {kgf} (mm) (g)
Grease Oil
d D B B1 r Open Open Open Single shielded Double shielded da db Da ra
min. Cr Cor Cr Cor ZS·ZZS ZS min. max. max. max. approx.
3.175 0.1250 9.525 0.3750 — — 2.779 0.1094 0.1 241 76 25 8.0 53 000 63 000 — SR 2X52 ZS SR 2X52 ZZS 3.9 3.9 8.7 0.1 1.0
10.100 0.3976 — — 2.380 0.0937 0.1 264 87 27 9.0 63 000 75 000 — SR 144X100 ZS SR 144X100 ZZS 3.9 3.9 9.3 0.1 1.2
10.414 0.4100 — — 2.380 0.0937 0.1 264 87 27 9.0 63 000 75 000 — SR 174X5 ZS SR 174X5 ZZS 3.9 3.9 9.6 0.1 1.2

4.762 0.1875 10.100 0.3976 — — 2.779 0.1094 0.1 305 119 31 12 53 000 63 000 — SR 156X100 ZS SR 156X100 ZZS 5.5 5.5 9.3 0.1 1.0
10.414 0.4100 — — 2.779 0.1094 0.1 305 119 31 12 53 000 63 000 — SR 156X101 ZS SR 156X101 ZZS 5.5 5.5 9.6 0.1 1.1
12.700 0.5000 2.779 0.1094 — — 0.1 605 216 62 22 50 000 60 000 SR 186X1 — — 5.6 11.9 0.1 1.8

12.700 0.5000 — — 3.967 0.1562 0.1 605 216 62 22 50 000 60 000 — SR 186X2 ZS SR 186X2 ZZS 5.6 5.9 11.9 0.1 2.6
14.463 0.5694 4.978 0.1960 4.978 0.1960 0.3 1 110 385 113 40 43 000 53 000 SR 3X31 SR 3X31 ZS SR 3X31 ZZS 6.5 6.5 12.9 0.3 4.0
22.225 0.8750 4.978 0.1960 4.978 0.1960 0.3 1 260 495 128 50 43 000 53 000 SR 3X23 SR 3X23 ZS SR 3X23 ZZS 6.8 8.4 20.6 0.3 13

Remark These bearings are made of stainless steel.

48 49
Angular contact ball bearings
B ra
r r1
Metric series
700C r ra

D d Da da
Bore diameter
4 – 9 mm

Boundary dimensions Basic load ratings Limiting speeds (min-1) Bearing Abutment and fillet dimensions Mass
(mm) (N) {kgf} numbers (mm) (g)
d D B r r1 Cr Cor Cr Cor Grease Oil da Da ra
min. min. min. max. max. approx.
4 16 5 0.3 0.15 1 700 660 174 67 53 000 71 000 734C 6.5 13.5 0.3 5.3

5 16 5 0.3 0.15 1 700 660 174 66 53 000 71 000 725C 7.5 13.5 0.3 4.5

6 17 6 0.3 0.15 2 030 795 204 81 50 000 67 000 706C 8.5 14.5 0.3 5.5
19 6 0.3 0.15 2 390 1 000 243 102 48 000 63 000 726C 8.5 16.5 0.3 7.8

7 19 6 0.3 0.15 2 390 1 000 243 102 48 000 63 000 707C 9.5 16.5 0.3 7.4

8 22 7 0.3 0.15 3 550 1 540 360 157 43 000 56 000 708C 10.5 19.5 0.3 12
24 8 0.3 0.15 3 600 1 600 365 164 40 000 53 000 728C 10.5 21.5 0.3 16

9 24 7 0.3 0.15 3 600 1 600 365 164 40 000 53 000 709C 11.5 21.5 0.3 14

Remarks 1. The tolerance classes for this type of bearing are classes 5 and 4.
2. Please contact NSK regarding separable bearings or inch series bearings.

Extra-thin-section deep groove ball bearings

B
Metric series r ra

r ra
SMT
Bore diameter D d Da da

10 – 15 mm

Boundary dimensions Basic load ratings Limiting speeds (min -1) Bearing Abutment and fillet dimensions Mass
(mm) (N) {kgf} numbers (mm) (g)
d D B r Cr Cor Cr Cor Grease Oil da Da ra
min. min. max. max. approx.
10 15 3 0.15 815 410 83 42 36 000 43 000 SMT 1510 11.2 13.8 0.15 1.4

15 20 3.5 0.15 800 470 82 48 30 000 36 000 SMT 2015 16.2 18.8 0.15 2.2

Remarks 1. These bearings are made of stainless steel.

2. The tolerance classes for this type of bearing are nomal and class 6.
3. The radial internal clearance for this type of bearing is specified by ISO 5593 Rolling bearings-Radial internal clearance.

50 51
Appendices
Page
Appendix Table 1 Conversion from SI (International Units)
system ...................................................... 54 – 55

Appendix Table 2 N – kgf Force conversion table ....................... 56

Appendix Table 3 Kg – 1b Mass conversion table ....................... 57

Appendix Table 4 °C – °F Temperature conversion table ........... 58

Appendix Table 5 Viscosity conversion table .............................. 59

Appendix Table 6 Inch-mm Dimension conversion table ............ 60

Appendix Table 7 Hardness conversion table ............................. 61

Appendix Table 8 Values of standard tolerance grades IT ... 62 – 63

Appendix Table 9 Physical and mechanical properties

of materials ...................................................... 64

53
 Appendix Table 1 Conversion from SI International Units System

Comparison of SI, CGS, and Engineering Units Prefixes Used In SI System

Units
Accelera- Force
Unit
Length Mass Time Temp. tion Stress Pressure Energy Power Multiples Prefix Symbols Multiples Prefix Symbols
System
–
1018 Exa E 10–1 Deci d
SI m kg s K m/s2 N Pa Pa J W 1015 Peta P 10–2 Centi c
1012 Tera T 10 3 Milli m
–
CGS System cm g s Gal dyn dyn/cm2 dyn/cm2 erg erg/s 109 Giga G 10–6 Micro p
106 Mega M 10–9 Nano n
Engineering 103 Kilo k 10 12 Pico p
m kgf s2 /m s m/s2 kgf kgf/m2 kgf/m2 kgf m kgf m/s
Unit System –
102 Hecto h 10–15 Femto f
10 Deca da 10 18 Ato a

Conversion Factors from SI Units Conversion Factors from SI Units Continued

SI Units Units other than SI Conversion Factors from SI Units Units other than SI Conversion factors
Parameter Parameter
SI Units from SI Units
Names of Units Symbols Name of Units Symbols Names of Units Symbols Names of Units Units

Angle Radian rad Degree 180/ Pressure Pascal Pa Kilogram-force per square meter kgf/m2 1/9.806 65
Minute 10 800/ (Newton per square meter) N/m 2 Water Column mH2O 1/9.806 6510 3

Second 648 000/ Mercury Column mmHg 760/ 1.013 25 10 5

Torr Torr 760/ 1.013 25 10 5
Length Meter m Micron p 10 6 Bar bar 10–5
Angstrom 10 10 Atmosphere 1/1.013 2510 5
atm
Area Square meter m2 Are a 10 –2
Hectare ha 10 –4 Energy Joule J Erg erg 10 7
(Newton meter) N ·m Calorie (International) cal IT 1/4.186 8
Volume Cubic meter m3 Liter l L 10 3 Kilogram-force meter kgf·m 1/9.806 65
Deciliter dl dL 10 4 Kilowatt hour kW·h 1/3.610 6

–7
French horse power hour PS··h 3.776 7210
Time Second s Minute min 1/60
Hour h 1/3 600 Work Watt
W Kilogram-force meter per second kgf·m/s 1/9.806 65
Day d 1/86 400 (Joule per second)
J/s Kilocalorie per hour kcal/h 1/1.163
French horse power PS 1/735.498 8
Frequency Hertz Hz Cycle s–1 1
Viscosity, Pascal second Pa·s Poise P 10
Speed of Rotation Revolution per second s–1 Revolution per minute rpm 60
Viscosity Index
Speed Meter per second m/s Kilometer per hour km/h 3 600/1 000 Kinematic Viscosity, Square meter per second m2/s Stokes St 10 4
Knot kn 3 600/1 852 Kinematic Viscosity
Index Centistokes 10 6
Acceleration Meter per second per second m/s2 Gal Gal 10 2 1
g g 1/9.806 65 Temperature Kelvin, Degree celsius K, Degree (See Note ( ))

Mass Kilogram kg Ton t 10 –3 Electric Current,

Ampere A Ampere A 1
Magnetomotive Force
Force Newton N Kilogram-force kgf 1/9.806 65 Voltage,
Volt V (Watts per ampere) W/A 1
Ton-force tf 1/9.806 6510 3
Electromotive Force
Dyne dyn 10 5 Magnetic Field 3
Ampere per meter A/m Oersted Oe 4/10
Strength
Torque or Moment Newtonmeter N m Kilogram-force meter kgf m 1/9.806 65
Magnetic Flux Tesla T Gauss Gs 10 4
Stress Pascal Pa Kilogram-force per square centimeter kgf/cm 2
1/9.806 6510 4
Density Gamma 10 9
N/m 2 Kilogram-force per square millimeter kgf/mm2 1/9.806 6510 6

Electrical Resistance Ohm (Volts per ampere) V/A 1

Note (1) The conversion from TK into C is = T 273.15 but for a temperature difference, it is dT = d. However, dT and d represent
temperature differences measured using the Kelvin and Celsius scales respectively.
Remarks The names and symbols in ( ) are equivalent to those directly above them or on their left.
Example of conversion 1 N = 1/9.806 65 kgf

54 55
 Appendix Table 2 N - kgf Conversion Table Appendix Table 3 kg–lb Conversion Table

How to use this table For example, to convert 10 N into kgf, read the figure in the right kgf How to use this table For example, to convert 10 kg into lb, read the figure in the right lb
column adjacent to the 10 in the center column in the 1st block. This column adjacent to the 10 in the center column in the 1st block. This
means that 10 N is 1.01997 kgf. To convert 10 kgf into N, read the means that 10 kg is 22.046 lb. To convert 10 lb into kg, read the figure
figure in the left N column of the same row, which indicates that the
1 N 0.1019716 kgf in the left kg column of the same row, which indicates that the
1 kg 2.2046226 1b
answer is 98.066 N. 1 kgf 9.80665 N answer is 4.536 kg. 1 1b 0.45359237 kg

N kgf N kgf N kgf kg lb kg lb kg lb

9.8066 1 0.1020 333.43 34 3.4670 657.05 67 6.8321 0.454 1 2.205 15.422 34 74.957 30.391 67 147.71
19.613 2 0.2039 343.23 35 3.5690 666.85 68 6.9341 0.907 2 4.409 15.876 35 77.162 30.844 68 149.91
29.420 3 0.3059 353.04 36 3.6710 676.66 69 7.0360 1.361 3 6.614 16.329 36 79.366 31.298 69 152.12
39.227 4 0.4079 362.85 37 3.7729 686.47 70 7.1380 1.814 4 8.818 16.783 37 81.571 31.751 70 154.32
49.033 5 0.5099 372.65 38 3.8749 696.27 71 7.2400 2.268 5 11.023 17.237 38 83.776 32.205 71 156.53

58.840 6 0.6118 382.46 39 3.9769 706.08 72 7.3420 2.722 6 13.228 17.690 39 85.980 32.659 72 158.73
68.647 7 0.7138 392.27 40 4.0789 715.89 73 7.4439 3.175 7 15.432 18.144 40 88.185 33.112 73 160.94
78.453 8 0.8158 402.07 41 4.1808 725.69 74 7.5459 3.629 8 17.637 18.597 41 90.390 33.566 74 163.14
88.260 9 0.9177 411.88 42 4.2828 735.50 75 7.6479 4.082 9 19.842 19.051 42 92.594 34.019 75 165.35
98.066 10 1.0197 421.69 43 4.3848 745.31 76 7.7498 4.536 10 22.046 19.504 43 94.799 34.473 76 167.55

107.87 11 1.1217 431.49 44 4.4868 755.11 77 7.8518 4.990 11 24.251 19.958 44 97.003 34.927 77 169.76
117.68 12 1.2237 441.30 45 4.5887 764.92 78 7.9538 5.443 12 26.455 20.412 45 99.208 35.380 78 171.96
127.49 13 1.3256 451.11 46 4.6907 774.73 79 8.0558 5.897 13 28.660 20.865 46 101.41 35.834 79 174.17
137.29 14 1.4276 460.91 47 4.7927 784.53 80 8.1577 6.350 14 30.865 21.319 47 103.62 36.287 80 176.37
147.10 15 1.5296 470.72 48 4.8946 794.34 81 8.2597 6.804 15 33.069 21.772 48 105.82 36.741 81 178.57

156.91 16 1.6315 480.53 49 4.9966 804.15 82 8.3617 7.257 16 35.274 22.226 49 108.03 37.195 82 180.78
166.71 17 1.7335 490.33 50 5.0986 813.95 83 8.4636 7.711 17 37.479 22.680 50 110.23 37.648 83 182.98
176.52 18 1.8355 500.14 51 5.2006 823.76 84 8.5656 8.165 18 39.683 23.133 51 112.44 38.102 84 185.19
186.33 19 1.9375 509.95 52 5.3025 833.57 85 8.6676 8.618 19 41.888 23.587 52 114.64 38.555 85 187.39
196.13 20 2.0394 519.75 53 5.4045 843.37 86 8.7696 9.072 20 44.092 24.040 53 116.84 39.009 86 189.60

205.94 21 2.1414 529.56 54 5.5065 853.18 87 8.8715 9.525 21 46.297 24.494 54 119.05 39.463 87 191.80
215.75 22 2.2434 539.37 55 5.6084 862.99 88 8.9735 9.979 22 48.502 24.948 55 121.25 39.916 88 194.01
225.55 23 2.3453 549.17 56 5.7104 872.79 89 9.0755 10.433 23 50.706 25.401 56 123.46 40.370 89 196.21
235.36 24 2.4473 558.98 57 5.8124 882.60 90 9.1774 10.886 24 52.911 25.855 57 125.66 40.823 90 198.42
245.17 25 2.5493 568.79 58 5.9144 892.41 91 9.2794 11.340 25 55.116 26.308 58 127.87 41.277 91 200.62

254.97 26 2.6513 578.59 59 6.0163 902.21 92 9.3814 11.793 26 57.320 26.762 59 130.07 41.730 92 202.83
264.78 27 2.7532 588.40 60 6.1183 912.02 93 9.4834 12.247 27 59.525 27.216 60 132.28 42.184 93 205.03
274.59 28 2.8552 598.21 61 6.2203 921.83 94 9.5853 12.701 28 61.729 27.669 61 134.48 42.638 94 207.23
284.39 29 2.9572 608.01 62 6.3222 931.63 95 9.6873 13.154 29 63.934 28.123 62 136.69 43.091 95 209.44
294.20 30 3.0591 617.82 63 6.4242 941.44 96 9.7893 13.608 30 66.139 28.576 63 138.89 43.545 96 211.64

304.01 31 3.1611 627.63 64 6.5262 951.25 97 9.8912 14.061 31 68.343 29.030 64 141.10 43.998 97 213.85
313.81 32 3.2631 637.43 65 6.6282 961.05 98 9.9932 14.515 32 70.548 29.484 65 143.30 44.452 98 216.05
323.62 33 3.3651 647.24 66 6.7301 970.86 99 10.095 14.969 33 72.753 29.937 66 145.51 44.906 99 218.26

56 57
 Appendix Table 4 ˚C - ˚F Conversion Table Appendix Table 5 Viscosity Conversion Table

How to use this table For example, to convert 38 ˚C into ˚F, read the figure in the right ˚F 5 F
column adjacent to the 38 in the center column in the 2nd block. This C 32
9
means that 38 ˚C is 100.4 ˚F. To convert 38 ˚ into ˚C, read the figure
in the left ˚C column of the same row, which indicates that the answer F 32 9C
is 3.3 ˚C. 5

Saybolt No.1 Type Saybolt No.1 Type

˚C ˚F ˚C ˚F ˚C ˚F ˚C ˚F Kinematic Universal Redwood Engler Kinematic Universal Redwood Engler
Viscosity SUS (sec) R (sec) E (degree) Viscosity SUS (sec) R (sec) E (degree)
mm2/s mm2/s
–73.3 –100 –148.0 0.0 32 89.6 21.7 71 159.8 43.3 110 230 100 ˚F 210 ˚F 50 ˚C 100 ˚C 100 ˚F 210 ˚F 50 ˚C 100 ˚C
–62.2 – 80 –112.0 0.6 33 91.4 22.2 72 161.6 46.1 115 239
–51.1 – 60 – 76.0 1.1 34 93.2 22.8 73 163.4 48.9 120 248 2 32.6 32.8 30.8 31.2 1.14 35 163 164 144 147 4.70
–40.0 – 40 – 40.0 1.7 35 95.0 23.3 74 165.2 51.7 125 257 3 36.0 36.3 33.3 33.7 1.22 36 168 170 148 151 4.83
–34.4 – 30 – 22.0 2.2 36 96.8 23.9 75 167.0 54.4 130 266 4 39.1 39.4 35.9 36.5 1.31 37 172 173 153 155 4.96
5 42.3 42.6 38.5 39.1 1.40 38 177 178 156 159 5.08
–28.9 – 20 – 6 45.5 45.8 41.1 41.7 1.48 39 181 183 160 164 5.21
4.0 2.8 37 98.6 24.4 76 168.8 57.2 135 275
–23.3 – 10 14.0 3.3 38 100.4 25.0 77 170.6 60.0 140 284
–17.8 0 32.0 3.9 39 102.2 25.6 78 172.4 65.6 150 302
–17.2 1 33.8 4.4 40 104.0 26.1 79 174.2 71.1 160 320 7 48.7 49.0 43.7 44.3 1.56 40 186 187 164 168 5.34
–16.7 2 35.6 5.0 41 105.8 26.7 80 176.0 76.7 170 338 8 52.0 52.4 46.3 47.0 1.65 41 190 192 168 172 5.47
9 55.4 55.8 49.1 50.0 1.75 42 195 196 172 176 5.59
10 58.8 59.2 52.1 52.9 1.84 43 199 201 176 180 5.72
–16.1 3 37.4 5.6 42 107.6 27.2 81 177.8 82.2 180 356 11 62.3 62.7 55.1 56.0 1.93 44 204 205 180 185 5.85
–15.6 4 39.2 6.1 43 109.4 27.8 82 179.6 87.8 190 374
–15.0 5 41.0 6.7 44 111.2 28.3 83 181.4 93.3 200 392
–14.4 6 42.8 7.2 45 113.0 28.9 84 183.2 98.9 210 410 12 65.9 66.4 58.2 59.1 2.02 45 208 210 184 189 5.98
–13.9 7 44.6 7.8 46 114.8 29.4 85 185.0 104.4 220 428 13 69.6 70.1 61.4 62.3 2.12 46 213 215 188 193 6.11
14 73.4 73.9 64.7 65.6 2.22 47 218 219 193 197 6.24
15 77.2 77.7 68.0 69.1 2.32 48 222 224 197 202 6.37
–13.3 8 46.4 8.3 47 116.6 30.0 86 186.8 110.0 230 446 16 81.1 81.7 71.5 72.6 2.43 49 227 228 201 206 6.50
–12.8 9 48.2 8.9 48 118.4 30.6 87 188.6 115.6 240 464
–12.2 10 50.0 9.4 49 120.2 31.1 88 190.4 121.1 250 482
–11.7 11 51.8 10.0 50 122.0 31.7 89 192.2 148.9 300 572
–11.1 17 85.1 85.7 75.0 76.1 2.54 50 231 233 205 210 6.63
12 53.6 10.6 51 123.8 32.2 90 194.0 176.7 350 662 18 89.2 89.8 78.6 79.7 2.64 55 254 256 225 231 7.24
19 93.3 94.0 82.1 83.6 2.76 60 277 279 245 252 7.90
–10.6 13 55.4 11.1 52 125.6 32.8 91 195.8 204 400 752 20 97.5 98.2 85.8 87.4 2.87 65 300 302 266 273 8.55
–10.0 14 57.2 11.7 53 127.4 33.3 92 197.6 232 450 842 21 102 102 89.5 91.3 2.98 70 323 326 286 294 9.21
– 9.4 15 59.0 12.2 54 129.2 33.9 93 199.4 260 500 932
– 8.9 16 60.8 12.8 55 131.0 34.4 94 201.2 288 550 1022
– 8.3 17 62.6 13.3 56 132.8 35.0 95 203.0 316 600 1112 22 106 107 93.3 95.1 3.10 75 346 349 306 315 9.89
23 110 111 97.1 98.9 3.22 80 371 373 326 336 10.5
24 115 115 101 103 3.34 85 394 397 347 357 11.2
– 7.8 18 64.4 13.9 57 134.6 35.6 96 204.8 343 650 1202 25 119 120 105 107 3.46 90 417 420 367 378 11.8
– 7.2 19 66.2 14.4 58 136.4 36.1 97 206.6 371 700 1292 26 123 124 109 111 3.58 95 440 443 387 399 12.5
– 6.7 20 68.0 15.0 59 138.2 36.7 98 208.4 399 750 1382
– 6.1 21 69.8 15.6 60 140.0 37.2 99 210.2 427 800 1472
– 5.6 22 71.6 16.1 61 141.8 37.8 100 212.0 454 850 1562 27 128 129 112 115 3.70 100 464 467 408 420 13.2
28 132 133 116 119 3.82 120 556 560 490 504 15.8
29 137 138 120 123 3.95 140 649 653 571 588 18.4
– 5.0 23 73.4 16.7 62 143.6 38.3 101 213.8 482 900 1652
– 30 141 142 124 127 4.07 160 742 747 653 672 21.1
4.4 24 75.2 17.2 63 145.4 38.9 102 215.6 510 950 1742
– 3.9 25 77.0 17.8 64 147.2 39.4 103 217.4 538 1 000 1832 31 145 146 128 131 4.20 180 834 840 734 757 23.7
– 3.3 26 78.8 18.3 65 149.0 40.0 104 219.2 593 1 100 2012
– 2.8 27 80.6 18.9 66 150.8 40.6 105 221.0 649 1 200 2192
32 150 150 132 135 4.32 200 927 933 816 841 26.3
33 154 155 136 139 4.45 250 1 159 1 167 1 020 1 051 32.9
– 2.2 28 82.4 19.4 67 152.6 41.1 106 222.8 704 1 300 2372 34 159 160 140 143 4.57 300 1 391 1 400 1 224 1 241 39.5
– 1.7 29 84.2 20.0 68 154.4 41.7 107 224.6 760 1 400 2552
– 1.1 30 86.0 20.6 69 156.2 42.2 108 226.4 816 1 500 2732 Remarks 1 mm2s 1 cSt
– 0.6 31 87.8 21.1 70 158.0 42.8 109 228.2 871 1 600 2912

58 59
61
 Appendix Table 8 Values of Standard Tolerance Grades IT

Standard Grades
Basic Size Basic Size
(mm) (mm)
IT1 IT2 IT3 IT4 IT5 IT6 IT7 IT8 IT9 IT10 IT11 IT12 IT13 IT14 IT15 IT16 IT17 IT18

over incl. Tolerances (pm) Tolerances (mm) over incl.

— 3 0.8 1.2 2 3 4 6 10 14 25 40 60 0.10 0.14 0.25 0.40 0.60 1.00 1.40 — 3

3 6 1 1.5 2.5 4 5 8 12 18 30 48 75 0.12 0.18 0.30 0.48 0.75 1.20 1.80 3 6

6 10 1 1.5 2.5 4 6 9 15 22 36 58 90 0.15 0.22 0.36 0.58 0.90 1.50 2.20 6 10

10 18 1.2 2 3 5 8 11 18 27 43 70 110 0.18 0.27 0.43 0.70 1.10 1.80 2.70 10 18

18 30 1.5 2.5 4 6 9 13 21 33 52 84 130 0.21 0.33 0.52 0.84 1.30 2.10 3.30 18 30

30 50 1.5 2.5 4 7 11 16 25 39 62 100 160 0.25 0.39 0.62 1.00 1.60 2.50 3.90 30 50

50 80 2 3 5 8 13 19 30 46 74 120 190 0.30 0.46 0.74 1.20 1.90 3.00 4.60 50 80

80 120 2.5 4 6 10 15 22 35 54 87 140 220 0.35 0.54 0.87 1.40 2.20 3.50 5.40 80 120

120 180 3.5 5 8 12 18 25 40 63 100 160 250 0.40 0.63 1.00 1.60 2.50 4.00 6.30 120 180

180 250 4.5 7 10 14 20 29 46 72 115 185 290 0.46 0.72 1.15 1.85 2.90 4.60 7.20 180 250

250 315 6 8 12 16 23 32 52 81 130 210 320 0.52 0.81 1.30 2.10 3.20 5.20 8.10 250 315

315 400 7 9 13 18 25 36 57 89 140 230 360 0.57 0.89 1.40 2.30 3.60 5.70 8.90 315 400

400 500 8 10 15 20 27 40 63 97 155 250 400 0.63 0.97 1.55 2.50 4.00 6.30 9.70 400 500

500 630 9 11 16 22 32 44 70 110 175 280 440 0.70 1.10 1.75 2.80 4.40 7.00 11.00 500 630

630 800 10 13 18 25 36 50 80 125 200 320 500 0.80 1.25 2.00 3.20 5.00 8.00 12.50 630 800

800 1 000 11 15 21 28 40 56 90 140 230 360 560 0.90 1.40 2.30 3.60 5.60 9.00 14.00 800 1 000

1 000 1 250 13 18 24 33 47 66 105 165 260 420 660 1.05 1.65 2.60 4.20 6.60 10.50 16.50 1 000 1 250

1 250 1 600 15 21 29 39 55 78 125 195 310 500 780 1.25 1.95 3.10 5.00 7.80 12.50 19.50 1 250 1 600

1 600 2 000 18 25 35 46 65 92 150 230 370 600 920 1.50 2.30 3.70 6.00 9.20 15.00 23.00 1 600 2 000

2 000 2 500 22 30 41 55 78 110 175 280 440 700 1 100 1.75 2.80 4.40 7.00 11.00 17.50 28.00 2 000 2 500

2 500 3 150 26 36 50 68 96 135 210 330 540 860 1 350 2.10 3.30 5.40 8.60 13.50 21.00 33.00 2 500 3 150

Remarks 1. Standard tolerance grades IT14 to IT18 shall not be used for basic sizes less than or equal to 1 mm.
2. Values for standard tolerance grades IT1 to IT5 for basic sizes over 500 mm are included for experimental use.

62 63
 Appendix Table 9 Physical and Mechanical Properties of Materials

Coefficient Modulus
of Linear of Direct Tensile Strength Yield Point
Specific Hardness Elasticity (MPa) (MPa) Elongation
Materials Expansion
Gravity (0 to 100 ˚C) (Brinell) (MPa) (%)
–1
{kgf/mm2} {kgf/mm2}
(K ) {kgf/mm2}

208 000 1 570 to 1 960 Bearing Conversion Tables

Bearing Steel (hardened) 7.83 12.5 10–6 650 to 740 — —
{21 200} {160 to 200}

Page
Martensitic Stainless Steel 200 000 1 960 1 860
SUS 440C 7.68 10.1 10 –6
580
{20 400} {200} {190}
— Conversion Table 1 Deep groove ball bearings open type
(Metric series) ................................................... 66
Mild (C=0.12 to 0.20 %) 206 000 373 to 471 216 to 294 Conversion Table 2 Deep groove ball bearings shielded type
7.86 11.6 10–6 100 to 130 24 to 36
Steel {21 000} {38 to 48} {22 to 30} (Metric series) ................................................... 67
Conversion Table 3 Deep groove ball bearings with flanged
Hard 206 000 539 to 686 333 to 451
Steel (C=0.3 to 0.5 %) 7.84 11.3 10–6 160 to 200 14 to 26 outer ring open type (Metric series) ................ 68
{21 000} {55 to 70} {34 to 46}
Conversion Table 4 Deep groove ball bearings with flanged
Austenitic Stainless Steel 193 000 588 245 outer ring shielded type (Metric series) .......... 69
SUS 304 8.03 16.3 10–6 150 60
{19 700} {60} {25} Conversion Table 5 Deep groove ball bearings open type
(Inch series) ...................................................... 70
More than
Gray Iron
FC200
7.3 10.4 10–6 223 200 — — Conversion Table 6 Deep groove ball bearings shielded type
{20}
Cast Iron
98 100 (Inch series) ....................................................... 70
{10 000}
Spheroidal
Less than
More than
More than
Conversion Table 7 Deep groove ball bearings with flanged
graphite Iron 7.0 11.7 10–6 400 —
FCD400
201 {41} 12 outer ring open type (Inch series) ................... 71
Conversion Table 8 Deep groove ball bearings with flanged
Aluminum 2.69 23.7 10–6 15 to 26
70 600 78 34
35 outer ring shielded type (Inch series) ............. 71
{7 200} {8} {3.5}
Conversion Table 9 Deep groove ball bearings with extended
92 200 147 inner ring open type (Inch series) ................... 72
Zinc 7.14 31 10–6 30 to 60 — 30 to 40
{9 400} {15} Conversion Table 10 Deep groove ball bearings with extended
inner ring shielded type (Inch series) ............. 72
123 000 196 69 Conversion Table 11 Deep groove ball bearings with extended
Copper 8.93 16.2 10–6 50 15 to 20
{12 500} {20} {7}
inner ring, flanged open type (Inch series) .... 73
294 to 343 Conversion Table 12 Deep groove ball bearings with extended
(Annealed) 45 {30 to 35} 65 to 75
103 000 inner ring, flanged shielded type
Brass 8.5 19.1 10–6 —
{10 500}
(Machined) 85 to 130 363 to 539 15 to 50 (Inch series) ...................................................... 73
{37 to 55}
Conversion Table 13 Ball bearings for synchros (Inch series).......... 74
Remarks The hardness of hardened bearing steel and martensitic stainless steel is usually expressed using the Rockwell C Scale,
but for comparison, it is converted into Brinell hardness.

64 65
Conversion
Conversion Table 1 Conversion Table 2
Deep groove ball bearings Deep groove ball bearings
Open type (Metric series) Shielded type (Metric series)

Bore diameter d Bore diameter d

NSK ADR FAG GRW RMB BARDEN MPB NMB NTN NSK ADR FAG GRW RMB BARDEN MPB NMB NTN
mm inch mm inch
1 0.0394 681 AX1 — 681 UL103 — — L-310 681 1.5 0.0591 681XZZ AX1.5ZZ — 68/1.5-2Z ULZ154 — UL15CHH L-415ZZ W68/1.5ZZA
MR31 — — — — — — L-310W51 — 691XZZ X1.5ZZ — 69/1.5-2Z — — — R-515ZZ W69/1.5ZZA
691 — — 691 — — — R-410 691 601XZZS — — — — — — R-615ZZ W60/1.5ZZA

1.2 0.0472 MR41X — — — — — — R-412 BC1.2-4 2 0.0787 682ZZ BX2ZZ — 682-2Z ULZ205 38M2SS UL20CHH L-520ZZ W682ZZA
MR52BZZ — — — — — — L-520ZZW52 WBC2-5ZZA
1.5 0.0591 681X AX1.5 — 68/1.5 UL154 — — R-415 68/1.5 692ZZ AX2ZZ — — — — — R-620ZZ W692ZZA
691X 619/1.5 MR69/1.5 69/1.5 R1550 19M1-5Y1 EL1.5C R-515 69/1.5
601X — — — — — — R-615 60/1.5 MR62ZZ — — — — — — R-620ZZY52 —
MR72ZZ — — — — — — R-720ZZY03 WBC2-7ZZA
2 0.0787 682 BX2 MR682 682 UL205 — UL20C L-520 682 602ZZ — — — — — — R-720ZZ W602ZZA
MR52B — — — — — — L-520W02 BC2-5
692 AX2 MR619/2 692 R2060 19M2Y1 EL2C R-620 692 2.5 0.0984 682XZZ AX2.5ZZ — 68/2.5-2Z ULZ256 38M2-5SS — L-625ZZ W68/2.5ZZA
692XZZ — — 69/2.5-2Z — — — R-725ZZ W69/2.5ZZA
MR62 — — — — — — R-620W52 BC2-6 602XZZ — — — — — — R-825ZZ W60/2.5ZZA
MR72 — — — — — — R-720Y52 BC2-7
602 — — — — — — R-720 602 3 0.1181 MR63ZZ — — — — — — L-630ZZ WA673ZZA
683AZZ AX3ZZ — 683-2Z 38M3SS UL30CHH L-730ZZ W683ZZA
2.5 0.0984 682X AX2.5 — 68/2.5 UL256 18M2-5 — L-625 68/2.5 693ZZ — — 693-2Z ULZ307 — — R-830ZZ W693ZZA
692X X2.5 — 69/2.5 — 19M2-5Y1 — R-725 69/2.5 —
MR82X — — — — — — R-825Y52 BC2.5-8 MR93ZZ — — — — — — R-930ZZY04 WBC3-9ZZA
602X 60/2.5 MR60/2.5 60/2.5 R2580 — — R-825 60/2.5 623ZZ 623ZZ 623.27 623-2Z RF310 2M3SSY1 EL3RHH R-1030ZZ 623ZZ
633ZZ — — — — — — — 633ZZ
3 0.1181 MR63 617/3 — — — — — L-630 673
683A AX3 MR618/3 683 UL307 — UL30C L-730 683 4 0.1575 MR74ZZ — — — — — — L-740X2ZZ WA674ZZA
MR83 X3 — 693/003 — — — R-830Y52 BC3-8 MR84ZZ — — — — — — L-840ZZ WBC4-8ZZA
684AZZ 638/4ZZ — 684-2Z ULZ409 38M455 UL40CHH L-940ZZ W684ZZA
693 619/3 — 693 — — — R-830 693
MR93 — — — — — — R-930Y52 BC3-9 MR104BZZ X4ZZ — — — — — L-1040ZZ WBC4-10ZZA
603 — — — — — — R-930 603 694ZZ AY4ZZ — 694-2Z — — — R-1140ZZ 694ZZ
604ZZ 604ZZ — 604-2Z — — — R-1240ZZ 604ZZ
623 623 MR623 623 R3100 2M3Y1 EL-3R R-1030 623
633 — — — — — — — 633 624ZZ 624ZZ 624.2Z 624-2Z RF413 2M4SS EL4RHH R-1340ZZ 624ZZ
634ZZ1 634ZZ MR634.27 634-2Z RV416 34SS 34RHH R-1640ZZ 634ZZ
4 0.1575 MR74 617/4 — — — — — L-740 674
MR84 — — — — — — L-840 BC4-8 5 0.1969 MR85ZZ — — — — — — L-850ZZ WA675ZZA
684A AX4 MR618/4 684 UL409 — UL40C L-940 684 MR95ZZ1 — — — — — — L-950X2ZZ WBC5-9ZZA
MR105ZZ — — — — — — L-1050ZZ WBC5-10ZZA
MR104B X4 — — — — — L-1040 BC4-10
694 AY4 — 694 — — — R-1140 694 685ZZ 638/5ZZ — 685-2Z ULZ511 — UL50CHH L-1150ZZ W685ZZ
604 604 — 604 — — — R-1240 604 695ZZ AY5ZZ — 695-2Z — — — R-1350ZZ 695ZZ
605ZZ — — 605-2Z — — — R-1450ZZ 605ZZ
624 624 MR624 624 R4130 2M4 EL4R R-1340 624
634 634 MR634 634 R4160 34 — R-1640 634 625ZZ1 625ZZ 625.2Z 625-2Z RV516 34-5SS EL5RHH R-1650ZZ 625ZZ
635ZZ1 635ZZ MR635.2Z 635-2Z RV519 35SS — R-1950ZZ 635ZZ
5 0.1969 MR85 617/5 — — — — — L-850 675
MR95 — — — — — — L-950 BC5-9 6 0.2362 MR106ZZ1 — — — — — — L-1060ZZ WA676ZZA
MR105 — — — — — — L-1050 BC5-10 MR126ZZ X6ZZ — — — — — L-1260ZZ WBC6-12ZZA
686AZZ 628/6ZZ — 686-2Z ULZ613 — UL60CHH L-1360ZZ W686ZZ
685 X5 MR618/5 685 UL511 — UL50C L-1150 685
695 AY5 — 695 — — — R-1350 695 696ZZ1 ZY6ZZ MR626.2Z 696-2Z — — — R-1560ZZ 696ZZ
605 — — 605 — — — R-1450 605 606ZZ — — — — — — R-1760ZZ 606ZZ
626ZZ1 626ZZ — 626-2Z RV619 36SS EL6RHH R-1960ZZ 626ZZ
625 625 MR625 625 R5160 34-5 EL5R R-1650 625 636ZZ — — — — — — — 636ZZ
635 635 MR635 635 R5190 35 — R-1950 635
7 0.2756 MR117ZZ — — — — — — L-1170ZZ WA677ZZA
6 0.2362 MR106 617/6 — — — — — L-1060 676 MR137ZZ — — — — — — L-1370ZZ WBC7-13ZZA
MR126 X6 — — — — — L-1260 BC6-12 687ZZ1 AX7ZZ — 687-2Z ULZ714 — UL70CH L-1470ZZ W687ZZ
686A AX6 MR618/6 686 UL613 — UL60C L-1360 686
697ZZ1 AY7ZZ — 697-2Z — — — — 697ZZ
696 AY6 — 696 — — — R-1560 696 607ZZ1 607ZZ 607.2Z 607-2Z — — EL7RHH R-1970ZZ 607ZZ
606 — — — — — — R-1760 606 627ZZ 627ZZ MR627.2Z 627-2Z RV722 37SS — R-2270ZZ 627ZZ
626 626 MR626 626 U6190 36 EL6R R-1960 626 637ZZ — — — — — — — 637ZZ
636 — — — — — — — 636
8 0.3150 MR128ZZ1 637/8ZZ — — — — — L-1280ZZ W678ZZA
7 0.2756 MR117 617/7 — — — — — L-1170 677 MR148ZZ — — — — — — L-1480ZZ WBC8-14ZZ
MR137 — — — — — — L-1370 BC7-13 688AZZ1 X8ZZ — — ULZ816 — — L-1680ZZ W688ZZ
687 AX7 618/7 687 UL714 — UL70C L-1470 687
698ZZ AY8ZZ — 698-2Z — 19M8SS — R-1980ZZ 698ZZ
697 AY7 — 697 — — — — 697 608ZZ 608ZZ MR608.2Z 608-2Z RV822 38SS EL8RHH R-2280ZZ 608ZZ
607 607 MR607 607 — — EL7R R-1970 607 628ZZ — — — — — — — 628ZZ
627 627 MR627 627 R7220 37 — R-2270 627 638ZZ — — — — — — — 638ZZ
637 — — — — — — — 637
9 0.3543 689ZZ1 X9ZZ — — ULZ917 — — L-1790ZZ W689ZZ
8 0.3150 MR128 617/8 — — — — — L-1280 678 699ZZ1 AY9ZZ — 699-2Z — 19M9SS — L-2090ZZ 699ZZ
MR148 — — — — — — L-1480 BC8-14 609ZZ 609ZZ 609.22 609-2Z — — — — 609ZZ
688A X8 MR618/8 688 UL816 — — L-1680 688 629ZZ 629ZZ MR629.2Z 629-2Z — 39SS — — 629ZZ
639ZZ — — — — — — — 639ZZ
698 AY8 — 698 — 19M8 — R-1980 698
608 608 MR608 608 R8220 38 EL8R R-2280 608 In case of ————— h
628 — — — — — — — 628 stainless steel S ———
—— W———
—— S ——
——— S ———
—— —————X S ——
——— S ——
——— SS ———
—— F —————
—
638 — — — — — — — 638

9 0.3543 689 X9 — 689 UL917 — — L-1790 689

699 AY9 — 699 — 19M9 — L-2090 699
609 609 609 609 609 — — — 609
629 629 MR629 629 — 39 — — 629
639 — — — — — — — 639
In case of ————— h
stainless steel S ————— W ————
— S ————
— S ———
—— ————
—X S ——
——— S ——
——— SS ————— F —————
—

66 67
Conversion
Conversion Table 3 Conversion Table 4
Deep groove ball bearings with flanged outer ring Deep groove ball bearings with flanged outer ring
Open type (Metric series) Shielded type (Metric series)

Bore diameter d Bore diameter d

NSK ADR GRW RMB BARDEN MPB NMB NTN NSK ADR GRW RMB BARDEN MPB NMB NTN
mm inch mm inch
1 0.0394 F681 — — — — — LF-310 FL681 1.5 0.591 F691XZZ FX1.5ZZ F69/1.5-2Z — — — RF-515ZZ FLW69/1.5ZZA
F691 — — — — — RF-410 FL691 F601XZZ — — — — — RF-615ZZ FLW60/1.5ZZA

1.2 0.0472 MF41X — — — — — RF-412 FLBC1.2-4 2 0.0787 F682ZZ FBX2ZZ F682-2Z ULKZ205 F682SS UL20FCHH LF-520ZZ FLW682ZZA
MF52BZZ — — — — — — —
1.5 0.0591 F681X FAX1.5 F68/1.5 ULK154 — — LF-415 FL68/1.5 F692ZZ FAX2ZZ — — F692SS — RF-620ZZ FLW692ZZA
F691X F619/1.5 F69/1.5 — F19M1-5Y1 — RF-515 FL69/1.5 MF72ZZ — — — — — RF-720ZZY03 FLWBC2-7ZZA
F601X — — — — — RF-615 EL60/1.5 F602ZZ — — — — — RF-720ZZ FLW602ZZA

2 0.0787 F682 FBX2 F682 ULK205 F682 UL20FC LF-520 FL682 2.5 0.0984 F682XZZ FAX2.5ZZ F68/2.5-2Z ULKZ256 F68/2.5SS — LF-625ZZ FLW68/2.5ZZA
MF52B — — — — — — — F692XZZ FX2.5ZZ F69/2.5-2Z — F69/2.5SS — RF-725ZZ FLW69/2.5ZZA
F692 FAX2 F692 RK2060 F692 — RF-620 FL692 F602XZZ — — — — — RF-825ZZ FLW60/2.5ZZA

MF62 — — — — — RF-620W52 FLBC2-6 3 0.1181 MF63ZZ — — — — — FL-630ZZ FLWA673ZZA

MF72 — — — — — RF-720Y52 — F683AZZ FAX3ZZ F683-2Z ULKZ307 F683SS UL30FCHH LF-730ZZ FLW683ZZA
F602 — — — — — RF-720 FL602 F693ZZ FX3ZZ F693-2Z RKF308 — — RF-830ZZ FLW693ZZA

2.5 0.0984 F682X FAX2.5 F68/2.5 ULK256 F68/2.5 — LF-625 FL68/2.5 MF93ZZ — — — — — RF-930ZZY04 FLWBC3-9ZZA
F692X FX2.5 F69/2.5 — F19M2-5Y1 — RF-725 FL69/2.5 F623ZZ F623ZZ F623-2Z RKF310 F623SS — RF-1030ZZ FL623ZZA
MF82X — — — — — RF-825Y52 FLBC2.5-8
F602X — — RK2580 — — RF-825 FL60/2.5 4 0.1575 MF74ZZ — — — — — LF-740ZZ FLWA674ZZA
MF84ZZ — — — — — LF-840ZZ FLWBC4-8ZZA
3 0.1181 MF63 — — — — — LF-630 FL673 F684AZZ F638/4ZZ F684-2Z ULKZ409 F684SS UL40FCHH LF-940ZZ FLW684ZZA
F683A FAX3 F683 ULK307 F683 UL30FC LF-730 FL683
MF83 — — — — — RF-830Y52 FLBC3-8 MF104BZZ — — — — — LF-1040ZZ FLAWBC4-10ZZA
F694ZZ — F694-2Z — F694SS — RF-1140ZZ FL694ZZA
F693 FX3 F693 — F693 — RF-830 FL693 F604ZZ — — — — — RF-1240ZZ FL604ZZ
MF93 — — — — — RF-930Y52 FLBC3-9
F603 — — — — — RF-930 FL603 F624ZZ F624ZZ F624-2Z — F624SS — RF-1340ZZ FL624ZZ
F634ZZ1 — F634-2Z — F634SS — RF-1640ZZ FL634ZZ
F623 F623 F623 RK3100 F623 — RF-1030 FL623
5 0.1969 MF85ZZ — — — — — LF-850ZZ FLWA675ZZA
4 0.1575 MF74 — — — — — LF-740 FL674 MF95ZZ1 — — — — — LF-950ZZ FLWBC5-9ZZA
MF84 — — — — — LF-840 FLBC4-8 MF105ZZ — — — — — LF-1050ZZ FLAWBC5-10ZZA
F684A FAX4 F684 ULK409 F684 UL40FC LF-940 FL684
F685ZZ F638/5ZZ F685-2Z ULKZ511 F685SS UL50FCHH LF-1150ZZ FLW685ZZA
MF104B — — — — — LF-1040 FLBC4-10 F695ZZ — F695-2Z — F695SS — RF-1350ZZ FL695ZZ
F694 — F694 — F694 — RF-1140 FL694 F605ZZ — F605-2Z — — — RF-1450ZZ FL605ZZ
F604 — — — — — RF-1240 FL604
F625ZZ1 — F625-2Z — F625SS — RF-1650ZZ FL625ZZ
F624 F624 F624 — F624 — RF-1340 FL624 F635ZZ1 — F635-2Z — F635SS — RF-1950ZZ FL635ZZ
F634 — F634 — F634 — RF-1640 —
6 0.2362 MF106ZZ1 — — — — — LF-1060ZZ FLWA676ZZA
5 0.1969 MF85 — — — — — LF-850 FL675 MF126ZZ — — — — — UF-1260ZZ FLAWBC6-12ZZA
MF95 — — — — — LF-950 FLBC5-9 F686AZZ F628/6ZZ F686-2Z ULKZ613 F686SS UL60FCHH LF-1360ZZ FLW686ZZA
MF105 — — — — — LF-1050 FLBC5-10
F696ZZ1 — F696-2Z — F696SS — RF-1560ZZ FL696ZZ
F685 FX5 F685 ULK511 F685 UL50FC LF-1150 FL685 F606ZZ — — — — — RF-1760ZZ FL606ZZ
F695 — F695 — F695 — RF-1350 FL695 F626ZZ1 — F626-27 — F626SS — — FL626ZZ
F605 — F605 — — — RF-1450 FL605
7 0.2756 MF117ZZ — — — — — LF-1170ZZ FLWA677ZZA
F625 — F625 — F625 — RF-1650 FL625 MF137ZZ — — — — — LF-1370ZZ FLAWBC7-13ZZA
F635 — F635 — F635 — RF-1950 — F687ZZ1 FAX7ZZ F687-2Z ULKZ714 F687SS UL70FCHH LF-1470ZZ FLW687ZZA

6 0.2362 MF106 — — — — — LF-1060 FL676 F697ZZ1 — F697-2Z — F697SS — — FL697ZZ

MF126 — — — — — LF-1260 FLBC6-12 F607ZZ1 F607ZZ F607-2Z — F607SS — — FL607ZZ
F686A FAX6 F686 — F686 UL60FC LF-1360 FL686 F627ZZ — F627-2Z — F627SS — RF-2270ZZ FL627ZZ

F696 — F696 — F696 — RF-1560 FL696 8 0.3150 MF128ZZ1 — — — — — LF-1280ZZ FLAW678ZZA

F606 — — — — — RF-1760 FL606 MF148ZZ — — — — — UF-1480ZZ FLWBC8-14ZZA
F626 — F626 — F626 — RF-1960 FL626 F688AZZ1 — — — F688SS — UF-1680ZZ FLW688ZZ

7 0.2756 MF117 — — — — — LF-1170 FL677 F698ZZ — F698-2Z — F698SS — — FL698ZZ

MF137 — — — — — LF-1370 FLBC7-13 F608ZZ F608ZZ F608-ZZ — F608SS — RF-2280ZZ FL608ZZ
F687 FAX7 F687 ULK714 F687 UL70FC LF-1470 FL687
9 0.3543 F689ZZ1 — — — F689SS — LF-1790ZZ FLW689ZZ
F697 — F697 — F697 — — FL697 F699ZZ1 — — — — — — FL699ZZ
F607 F607 F607 — F607 — — —
F627 — — — — — RF-2270 — In case of ————— h <None>
stainless steel S ———
—— W ————— S —————
— —————
—X S ————
—— S ————
—— SS ————
—— F ————
——
8 0.3150 MF128 — — — — — LF-1280 FL678
MF148 — — — — — LF-1480 FLBC8-14
F688A FX8 F688 ULK816 F688 — LF-1680 FL688

F698 — F698 — F698 — RF-1980 FL698

F608 F608 F608 — — — RF-2280 FL608

9 0.3543 F689 FX9 F689 — — — LF-1790 FL689

F699 — — — — — — —
In case of ————— h
stainless steel S ——
——— W ————— S —————
— —————
—X S ————
—— S ————
—— SS ————
—— F ————
——

68 69
Conversion
Conversion Table 5 Conversion Table 7
Deep groove ball bearings Deep groove ball bearings with flanged outer ring
Open type (Inch series) Open type (Inch series)

Bore diameter d Bore diameter d

NSK ADR FAG GRW RMB BARDEN MPB NMB NTN NSK ADR FAG GRW RMB BARDEN MPB NMB NTN
mm inch mm inch
1.016 0.0400 R09 R09 R0308 1016 UL1304 — 2C R1-2 R01 1.191 0.0469 FR0 FX3/64 RF0310 F1191 ULK1505 FR0 21/2FC RIF-21/2 FLR0
1.191 0.0469 R0 X3/64 R0310 1191 UL1505 R0 21/2C RI-21/2 R0 1.397 0.0550 FR1 FR1 RF0412 F1397 RK1706 FR1 3FC RIF-3 FLR1
1.397 0.0550 R1 R1 R0412 1397 R1706 R1 3C RI-3 R1 1.984 0.0781 FR1-4 FX5/64 RF0516 F5/64 RK2508 FR1-4 4FC RIF-4 FLR1-4
1.984 0.0781 R1-4 X5/64 R0516 BR5/64 R2508 R1-4 4C RI-4 R1-4 2.380 0.0937 FR133 FAX3/32 RF0612 F2380 ULK3006 FR133 3332FC RIF-3332 FLR133
FR1-5 FX3/32 RF620 F3/32 RK3010 FR1-5 5FC RIF-5 FLR1-5
2.380 0.0937 R133 AX3/32 R0612 2380 UL3006 R133 3332C RI-3332 R133
R1-5 X3/32 R620 BR3/32 R3010 R1-5 5C RI-5 R1-5 3.175 0.1250 FR144 FAX1/8 RF0816 F3175 ULK4008 FR144 418FC RIF-418 RIF-144
FR2-5 FX1/8 RF820 F1/8A RK4010 FR2-5 518FC RIF-518 FLR2-5
3.175 0.1250 R144 AX1/8 R0816 3175 UL4008 R144 418C RI-418 R144 FR2-6 — RF824 F1/8A/6 — FR2-6 618FC RIF-618 FLR2-6
R2-5 X1/8 R820 BR1/8A R4010 R2-5 518C RI-518 R2-5 FR2 FR2 RF2 F1/88 RK4012 FR2 R2FC RF-2 FLR2
R2-6 — R824 BR1/8A/6 — R2-6 618C RI-618 R2-6
3.967 0.1562 FR155 FX5/32 RF1020 F3967 ULK5010 FR155 5532FC RIF-5532 FLR155
R2 R2 R2 BR1/8B R4012 R2 R2C R-2 R2
R2A R2A R2A BR1/8B/083 — R2A R2AC — RA2 4.762 0.1875 FR156 FAX3/16 RF1220 F4763A ULK6010 FR156 5632FC RIF-5632 FLR156
FR166 FX3/16 RF1224 F4763B ULK6012 FR166 6316FC RIF-6632 FLR166
3.967 0.1562 R155 X5/32 R1020 3967 UL5010 R155 5532C RI-5532 R155 FR3 FY3/16 RF3 — RK6016 FR3 — — FLR3
4.762 0.1875 R156 AX3/16 R1220 4763A UL6010 R156 5632C RI-5632 R156 6.350 0.2500 FR168 FX1/4 RF1624 F6350A ULK8012 FR168 614FC RIF-614 FLR168
R166 X3/16 R1224 4763B UL6012 R166 6316C RI-6632 R166 FR188 FR188 RF1632 F6350B ULK8016 FR188 814FC RIF-814 FLR188
R3 Y3/16 R3 BR3/16 R6016 R3 R3C R-3 R3 FR4B FY1/4 RF4 F1/4A RK8020 FR4 R4FC RF-4 FLR4
6.350 0.2500 R168 X1/4 R1624 6350A UL8012 R168 614C RI-614 R168 7.938 0.3125 FR1810 — RF2032 F7938 — FR1810 8516FC RIF-8516 —
R188 R188 R1632 6350B UL8016 R188 814C RI-814 R188
R4B Y1/4 R4 BR1/4A R8020 R4 R4C R-4 R4 9.525 0.3750 FR6 — — — — — — — —
R4AA R4A R4A BR1/4 — R4A R4AR RI-1214 —
In case of
7.938 0.3125 R1810 — R2032 7938 — R1810 8516C RI-8516 — S ———
—— W ———
—— S ———
—— S ———
—— ———
—— X S ———
—— S ———
—— SS ————— F ———
———
stainless steel
9.525 0.3750 R6 Y3/8 R6 BR3/8 — R6 R6R RI-1438 —
In case of
S ————
— W ———
—— S ———
—— S ———
—— ————
—X S ———
—— S ———
—— SS ————— F ————
——
stainless steel

Conversion Table 8
Deep groove ball bearings with flanged outer ring
Conversion Table 6 Shielded type (Inch series)
Deep groove ball bearings
Shielded type (Inch series)
Bore diameter d
NSK ADR FAG GRW RMB BARDEN MPB NMB NTN
mm inch
1.191 0.0469 FR0ZZ FX3/64ZZ RF0310.2Z F1191-2Z ULKZ1505 FR0SS 21/2FCHH RIF-21/2ZZ FLRA0ZZA
Bore diameter d
NSK ADR FAG GRW RMB BARDEN MPB NMB NTN 1.397 0.0550 FR1ZZ FR1ZZ RF0412.2Z F1397-2Z RKF1706 FR1SS 3FCHH RIF-3ZZ FLRA1ZZA
mm inch
1.984 0.0781 FR1-4ZZ FX5/64ZZ RF0516.2Z F5/64-2Z RKF2508 FR1-4SS 4FCHH RIF-4ZZ FLRA1-4ZZA
1.191 0.0469 R0ZZ X3/64ZZ R0310.2Z 1191-2Z ULZ1505 R0SS 21/2CHH RI-21/2ZZ RA0ZZA
2.380 0.0937 FR133ZZS FAX3/32ZZ RF0612.2Z F2380-2Z ULKZ3006 FR133SS 3332FCHH RIF-3332ZZ FLRA133ZZAS
1.397 0.0550 R1ZZ R1ZZ R0412.2Z 1397-2Z RF1706 R1S 3CHH RI-3ZZ RA1ZZ1 FR1-5ZZ FX3/32ZZ RF620.2Z F3/32-2Z RKF3010 FR1-5SS 5FCHH RIF-5ZZ FLRA1-5ZZA
1.984 0.0781 R1-4ZZ X5/64ZZ R0516.2Z BR5/64-2Z RF2508 R1-4SS 4CHH RI-4ZZ RA1-4ZZ1 3.175 0.1250 FR144ZZ FAX1/8ZZ RF0816.2Z F3175-2Z ULKZ4008 FR144SS 418FCHH RIF-418ZZ FLRA144ZZA
FR2-5ZZ FX1/8ZZ RF820.2Z F1/8A-2Z RKF4010 FR2-5SS 518FCHH RIF-518ZZ FLRA2-5ZZA
2.380 0.0937 R133ZZS AX3/32ZZ R0612.2Z 2380-2Z ULZ3006 R133SS 3332CHH RI-3332ZZ RA133ZZA FR2-6ZZS — RF824.2Z F1/8A/6-2Z — FR2-6SS 618FCHH RIF-618ZZ FLRA2-6ZZAS
R1-5ZZ X3/32ZZ R620.2Z BR3/32ZZ RF3010 R1-5SS 5CHH RI-5ZZ RA1-5ZZA FR2ZZ FR2ZZ RF2.2Z F1/8B-2Z RKF4012 FR2SS R2FCHH RF-2ZZ FLR2ZZA
3.175 0.1250 R144ZZ AX1/8ZZ R0816.2Z 3175-2Z ULZ4008 R144SS 418CHH RI-418ZZ RA144ZZA 3.967 0.1562 RF155ZZS FX5/32ZZ RF1020.2Z F3967-2Z ULKZ5010 FR155SS 5532FCHH RIF-5532ZZ FLRA155ZZAS
R2-5ZZ X1/8ZZ R820.2Z BR1/8A-2Z RF4010 R2-5SS 518CHH RI-518ZZ RA2-5ZZA
R2-6ZZS — R824.2Z BR1/8A/6-2Z — R2-6SS 618CHH RI-618ZZ RA2-6ZZA 4.762 0.1875 FR156ZZS FAX3/16ZZ RF1220.2Z F4763A-2Z ULKZ6010 FR156SS 5632FCHH RIF-5632ZZ FLRA156ZZAS
FR166ZZ FX3/16ZZ RF1224.2Z F4763B-2Z ULKZ6012 FR166SS 6316FCHH RIF-6632ZZ FLRA166ZZA
R2ZZ R2ZZ R2.2Z BR1/8B-2Z RF4012 R2SS R2CHH R-2ZZ R2ZZA FR3ZZ FY3/16ZZ RF3.2Z F3/16-2Z RKF6016 FR3SS R3FCHH RF-3ZZ FLRA3ZZ
R2AZZ R2AZZ R2A.2Z BR1/8B/083-2Z — R2ASS R2ACHH — RA2ZZA
6.350 0.2500 FR168ZZ FX1/4ZZ RF1624.2Z F6350A-2Z ULKZ8012 FR168SS 614FCHH RIF-614ZZ FLRA168ZZA
3.967 0.1562 R155ZZS X5/32ZZ R1020.2Z 3967-2Z ULZ5010 R155SS 5532CHH RI-5532ZZ RA155ZZA FR188ZZ FR188ZZ RF1632.2Z F6350B-2Z ULKZ8016 FR188SS 814FCHH RIF-814ZZ FLRA188ZZA
FR4BZZ FY1/4ZZ RF4.2Z F1/4A-2Z RKF8020 FR4SS R4FCHH RF-4ZZ FLR4ZZ
4.762 0.1875 R156ZZS AX3/16ZZ R1220.2Z 4763A-2Z ULZ6010 R156SS 5632CHH RI-5632ZZ RA156ZZA
R166ZZ X3/16ZZ R1224.2Z 4763B-2Z ULZ6012 R166SS 6316CHH RI-6632ZZ R166ZZA 7.938 0.3125 FR1810ZZ — RF2032.2Z F7938-2Z — FR1810SS 8516FCHH RIF-8516ZZ —
R3ZZ Y3/16ZZ R3.2Z BR3/16-2Z RF6016 R3SS R3CHH R-3ZZ RA3ZZ
9.525 0.3750 FR6ZZ FY3/8ZZ RF6.2Z — — FR6SS R6FRHH RIF-1438ZZ FLR6ZZ
6.350 0.2500 R168ZZ X1/4ZZ R1624.2Z 6350A-2Z ULZ8012 R168SS 614CHH RI-614ZZ R168ZZA
R188ZZ R188ZZ R1632.2Z 6350B-2Z ULZ8016 R188SS 814CHH RI-814ZZ RA188ZZA In case of
R4BZZ Y1/4ZZ R4.2Z BR1/4A-2Z RF8020 R4SS R4CHH R-4ZZ R4ZZ S ———
—— W ———
—— S ———
—— S ———
—— ———
—— X S ———
—— S ———
—— F ———
——— SS —————
stainless steel
R4AAZZ R4AZZ R4A.2Z BR1/4-2Z — R4ASS R4ARHH RI-1214ZZ RA4ZZ
7.938 0.3125 R1810ZZ — R2032.2Z 7938-2Z — R1810SS 8516CHH RI-8516ZZ —
9.525 0.3750 R6ZZ Y3/8ZZ R6.2Z BR3/8-2Z — R6SS R6RHH RI-1438ZZ R6ZZ
In case of
S ————
— W ———
—— S ———
—— S ———
—— ————
—X S ———
—— S ———
—— SS ————— F ————
——
stainless steel

70 71
Conversion
Conversion Table 9 Conversion Table 11
Deep groove ball bearings with extended inner ring Deep groove ball bearings with extended inner ring,
Open type (Inch series) Flanged, open type (Inch series)

Bore diameter d Bore diameter d

NSK ADR FAG GRW RMB BARDEN MPB NMB NTN NSK ADR FAG GRW RMB BARDEN MPB NMB NTN
mm inch mm inch
1.191 0.0469 RW0 LX3/64 RE0310 E1191 ULU1505 RW0 21/2CE RI-21/2EE RW0 1.191 0.0469 FRW0 FLX3/64 RFE0310 FE1191 ULKU1505 FRW0 21/2FCE RIF-21/2EE FLRW0
1.397 0.0550 RW1 LR1 RE0412 E1397 RU1706 RW1 3CE RI-3EE RW1 1.397 0.0550 FRW1 FLR1 RFE0412 FE1397 RKU1706 FRW1 3FCE RIF-3EE FLRW1
1.984 0.0781 RW1-4 LX5/64 RE0516 E5/64 — RW1-4 4CE RI-4EE RW1-4 1.984 0.0781 FRW1-4 FLX5/64 RFE0516 FE5/64 — FRW1-4 4FCE RIF-4EE FLRW1-4
2.380 0.0937 RW133 LAX3/32 RE0612 E2380 ULU3006 RW133 3332CE RI-3332EE RW133 2.380 0.0937 FRW133 FLAX3/32 RFE0612 FE2380 ULKU3006 FRW133 3332FCE RIF-3332EE FLRW133
RW1-5 LX3/32 RE620 E3/32 RU3010 RW1-5 5CE RI-5EE RW1-5 FRW1-5 FLX3/32 RFE620 FE3/32 RKU3010 FRW1-5 5FCE RIF-5EE FLRW1-5
3.175 0.1250 RW144 LAX1/8 RE0816 E3175 ULU4008 RW144 418CE RI-418EE RW144 3.175 0.1250 FRW144 FLAX1/8 RFE0816 FE3175 ULKU4008 FRW144 418FCE RIF-418EE FLRW144
RW2-5 LX1/8 RE820 E1/8A RU4010 RW2-5 518CE RI-518EE RW2-5 FRW2-5 FLX1/8 RFE820 FE1/8A RKU4010 FRW2-5 518FCE RIF-518EE FLRW2-5
RW2-6 — RE824 E1/8A/6 — RW2-6 618CE RI-618EE RW2-6 FRW2-6 — RFE824 FE1/8A/6 — FRW2-6 618FCE RIF-618EE FLRW2-6
RW2 LR2 RE2 E1/8B — RW2 R2CE R-2EE RW2 FRW2 FLR2 RFE2 FE1/8B — FRW2 R2FCE RF-2EE FLRW2
3.967 0.1562 RW155 LX5/32 RE1020 E3967 — RW155 5532CE RI-5532EE RW155 3.967 0.1562 FRW155 FLX5/32 RFE1020 FE3967 — FRW155 5532FCE RIF-5532EE FLRW155
4.762 0.1875 RW156 LAX3/16 RE1220 E4763A ULU6010 RW156 5632CE RI-5632EE RW156 4.762 0.1875 FRW156 FLAX3/16 RFE1220 FE4763A ULKU6010 FRW156 5632FCE RIF-5632EE FLRW156
RW166 LX3/16 RE1224 E4763B ULU6012 RW166 6316CE RI-6632EE RW166 FRW166 FLX3/16 RFE1224 FE4763B ULKU6012 FRW166 6316FCE RIF-6632EE FLRW166
6.350 0.2500 RW168 LX1/4 RE1624 E6350A ULU8012 RW168 614CE RI-614EE RW168 6.350 0.2500 FRW168 FLX1/4 RFE1624 FE6350A ULKU8012 FRW168 614FCE RIF-614EE FLRW168
RW188 LR188 RE1632 E6350B — RW188 814CE RI-814EE RW188 FRW188 FLR188 RFE1632 FE6350B — FRW188 814FCE RIF-814EE FLRW188
7.938 0.3125 RW1810 — RE2032 E7938 — RW1810 8516CE RI-8516EE — 7.938 0.3125 FRW1810 — RFE2032 FE7938 — FRW1810 8516FCE RIF-8516EE —
In case of In case of
S ————
— W ———
—— S ————
— S ————
— ———
—— X S ————
— S ————
— SS ————— F ————
—— S ——
——— W ———
—— S ——
——— S ——
——— ——
——— X S ——
——— S ——
——— SS ————— F ———
———
stainless steel stainless steel

Conversion Table 10 Conversion Table 12

Deep groove ball bearings with extended inner ring Deep groove ball bearings with extended inner ring,
Shielded type (Inch series) Flanged, shielded type (Inch series)

Bore diameter d Bore diameter d

NSK ADR FAG GRW RMB BARDEN MPB NMB NTN NSK ADR FAG GRW RMB BARDEN MPB NMB NTN
mm inch mm inch
1.191 RW0ZZ LX3/64ZZ 1/2 1/2 1/2 1/2
0.0469 RE0310.2Z E1191-2Z — — 2 CHHE RI-2 ZZEE RAW0ZZA 1.191 0.0469 FRW0ZZ FLX3/64ZZ RFE0310.2Z FE1191-2Z — — 2 FCHHE RIF-2 ZZEE FLRAW0ZZA
1.397 0.0550 RW1ZZ LR1ZZ RE0412.2Z E1397-2Z — — 3CHHE RI-3ZZEE RAW1ZZA 1.397 0.0550 FRW1ZZ FLR1ZZ RFE0412.2Z FE1397-2Z — — 3FCHHE RIF-3ZZEE FLRAW1ZZA
1.984 0.0781 RW1-4ZZ LX5/64ZZ RE0516.2Z E5/64-2Z — RW1-4SS 4CHHE RI-4ZZEE RAW1-4ZZA 1.984 0.0781 FRW1-4ZZ FLX5/64ZZ RFE0516.2Z FE5/64-2Z — FRW1-4SS 4FCHHE RIF-4ZZEE FLRAW1-4ZZA
2.380 0.0937 RW133ZZS LAX3/32ZZ RE0612.2Z E2380-2Z — RW133SS 3332CHHE RI-3332ZZEE RAW133ZZA 2.380 0.0937 FRW133ZZS FLAX3/32ZZ RFE0612.2Z FE2380-2Z — FRW133SS 3332FCHHE RIF-3332ZZEE FLRAW133ZZA
RW1-5ZZ LX3/32ZZ RE620.2Z E3/32-2Z — RW1-5SS 5CHHE RI-5ZZEE RAW1-5ZZA FRW1-5ZZ FLX3/32ZZ RFE620.2Z FE3/32-2Z — FRW1-5SS 5FCHHE RIF-5ZZEE FLRAW1-5ZZA
3.175 0.1250 RW144ZZ LAX1/8ZZ RE0816.2Z E3175-2Z ULUZ4008 RW144SS 418CHHE RI-418ZZEE RAW144ZZA 3.175 0.1250 FRW144ZZ FLAX1/8ZZ RFE0816.2Z FE3175-2Z ULKUZ4008 FRW144SS 418FCHHE RIF-418ZZEE FLRAW144ZZA
RW2-5ZZ LX1/8ZZ RE820.2Z E1/8A-2Z — RW2-5SS 518CHHE RI-518ZZEE RAW2-5ZZA FRW2-5ZZ FLX1/8ZZ RFE820.2Z FE1/8A-2Z — FRW2-5SS 518FCHHE RIF-518ZZEE FLRAW2-5ZZA
RW2-6ZZS — RE824.2Z E1/8A/6-2Z — RW2-6SS 618CHHE RI-618ZZEE RAW2-6ZZA FRW2-6ZZS — RFE824.2Z FE1/8A/6-2Z — FRW2-6SS 618FCHHE RIF-618ZZEE FLRAW2-6ZZA
RW2ZZ LR2ZZ RE2.2Z E1/8B-2Z — RW2SS R2CHHE R-2ZZEE RW2ZZA FRW2ZZ FLR2ZZ RFE2.2Z FE1/8B-2Z — FRW2SS R2FCHHE RF-2ZZEE FLRW2ZZA
3.967 0.1562 RW155ZZS LX5/32ZZ RE1020.2Z E3967-2Z ULUZ5010 RW155SS 5532CHHE RI-5532ZZEE RAW155ZZA 3.967 0.1562 FRW155ZZS FLX5/32ZZ RFE1020.2Z FE3967-2Z ULKUZ5010 FRW155SS 5532FCHHE RIF-5532ZZEE FLRAW155ZZA
4.762 0.1875 RW156ZZS LAX5/32ZZ RE1220.2Z E4763A-2Z ULUZ6010 RW156SS 5632CHHE RI-5632ZZEE RAW156ZZA 4.762 0.1875 FRW156ZZS FLAX3/16ZZ RFE1220.2Z FE4763A-2Z ULKUZ6010 FRW156SS 5632FCHHE RIF-5632ZZEE FLRAW156ZZA
RW166ZZ LX3/16ZZ RE1224.2Z E4763B-2Z ULUZ6012 RW166SS 6316CHHE RI-6632ZZEE RW166ZZA FRW166ZZ FLX3/16ZZ RFE1224.2Z FE4763B-2Z ULKUZ6012 FRW166SS 6316FCHHE RIF-6632ZZEE FLARW166ZZA
6.350 0.2500 RW168ZZ LX1/4ZZ RE1624.2Z E6350A-2Z ULUZ8012 RW168SS 614CHHE RI-614ZZEE RW168ZZA 6.350 0.2500 FRW168ZZ FLX1/4ZZ RFE1624.2Z FE6350A-2Z ULKUZ8012 FRW168SS 614FCHHE RIF-614ZZEE FLARW168ZZA
RW188ZZ LR188ZZ RE1632.2Z E6350B-2Z — RW188SS 814CHHE RI-814ZZEE RAW188ZZA FRW188ZZ FLR188ZZ RFE1632.2Z FE6350B-2Z — FRW188SS 814FCHHE RIF-814ZZEE FLRAW188ZZA
7.938 0.3125 RW1810ZZ — RE2032.2Z E7938-2Z — RW1810SS 8516CHHE RI-8516ZZEE — 7.938 0.3125 FRW1810ZZ — RFE2032.2Z FE7938-2Z — FRW1810SS 8516FCHHE RIF-8516ZZEE —
In case of In case of
S ————
— W ———
—— S ————
— S —————
— ———— X S ————
— S ————
— SS ————— F ————
—— S ——
——— W ————
— S ———
—— S —————
— ———— X S ——
——— S ———
—— SS ——
——— F ———
———
stainless steel stainless steel

72 73