Bearing interfaces

B 6 Bearing interfaces

The ISO tolerance system . . . . . . . . . . . . . . . . . . . . . . . . 141

Selecting its . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

Conditions of rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Magnitude of load 143
Temperature differences 143
Precision requirements 143
Design and material of the shaft and housing 143
Ease of mounting and dismounting 143
Axial displacement of the bearing in the non-locating
position 143

Tolerances for bearing seats and abutments 144

Tolerances for seats on hollow shafts 146

B.6 Bearing interfaces

Tolerances for tapered seats 147
Taper position 147
Checking tolerances 147

Surface texture of bearing seats 147

Seat tolerances for standard conditions 148

Bearings with a tapered bore 148

Tolerances and resultant its 153

Provisions for mounting and dismounting 176

Axial location of bearing rings 178

Bearings with a tapered bore 178
Abutments and illets 178

Radially free mounted bearings for axial load 179

Raceways on shafts and in housings 179

139
 Bearing interfaces

B 6 Bearing interfaces

Bearing seats on shafts and in housings, and

components which locate a bearing axially,
The ISO tolerance Selecting fits
have a signiicant impact on bearing perfor-
mance To fully exploit the load carrying abil-
system Fits can be selected by following the recom-
ity of a bearing, its rings or washers should mendations for bearing seat diameter toler-
be fully supported around their complete Fits for rolling bearings are typically speciied ances (Seat tolerances for standard condi-
circumference and across the entire width of with standard tolerance classes for holes and tions, page 148) These recommendations
the raceway Bearing seats should be manu- shafts as described in ISO 286-2 As bear- will provide adequate solutions for the
factured to adequate geometrical and ings are typically manufactured to ISO toler- majority of applications However, they do
dimensional tolerances and be uninter- ances (Tolerances, page 36), the selection of not cover all details of a speciic application
rupted by grooves, holes or other features the tolerance class for the bearing seat and so you may ind that adjustments may
In this section you can ind recommenda- determines the it The position and width of be necessary When selecting its, you should
tions and requirements for designing bear- the tolerance intervals of commonly used consider the following topics
ing interfaces, including: tolerance classes relative to the bearing bore
B.6 Bearing interfaces

and outside diameter tolerances are illus-

• criteria when selecting bearing its trated in ig. 1, which is valid for bearings
• recommended its for standard conditions with Normal tolerances and of medium size
• tables to help determine minimum, max- It is important to note that the ISO tolerance
imum and probable values of clearance or classes for rolling bearings and for holes and
interference between the bearing and its shafts are different The tolerances for each
seat size vary over the full range of actual sizes
• recommendations for specifying geomet- You should therefore select the respective
rical tolerances of bearing seats tolerance classes for bearing seats based on
• recommendations for the axial support of the actual bearing size for your application
bearing rings
• further design considerations for bearing
interfaces

140
 Selecting its

Fig. 1

Position and width of shaft and housing tolerance classes

B.6 Bearing interfaces

Outer diameter
tolerance interval + Loose it
0
– Transition it
F7 G7 G6 H10 H9 H8 H7 H6 J7 J6 JS7 JS6 Interference it
K7 K6 M6
M7
N6
N7
P6
P7

r7
p7 r6
p6
n6
n5
m6
k6 m5
j6 k5
j5 js6 js5
+ f6 g6 g5 h8 h6 h5 Interference it
0
– Transition it
Inner diameter Loose it
tolerance interval

141
 B.6 Bearing interfaces

Conditions of rotation • Stationary loads should be able to move axially in its hous-
These loads occur where both the bearing ing, a loose it must be used However, a
Conditions of rotation refer to the relative ring and the applied load are stationary or loose it can result in housing wear Where
motion between a bearing ring and the load both are rotating at the same speed this cannot be tolerated, either protect the
acting upon it (table 1). Essentially, there are Under these conditions, a bearing ring bearing seat surface or select a bearing
three different conditions: normally does not creep and there is no that accommodates the axial displacement
risk of fretting corrosion or wear In this within itself (cylindrical roller, needle roller
• Rotating loads case, the ring does not need to have an or CARB bearing) These bearings can be
These loads occur where either the bear- interference it mounted with an interference it for both
ing ring or the applied load is stationary rings
while the other rotates. A bearing ring • Direction of load indeterminate
mounted with a loose it will creep on its This refers to variable or alternating exter-
seat when subjected to a rotating load, nal loads, sudden load peaks, vibration or
and this can lead to fretting corrosion and unbalanced loads in high-speed applica-
eventually wear To prevent this from hap- tions These give rise to changes in the
pening, an adequate interference it, direction of load, which cannot be accur-
between the ring subjected to rotating ately described Where the direction of
load and its seat, is required For the pur- load is indeterminate and particularly
pose of selecting its, loads that oscillate where heavy loads are involved, there is a
(such as loads acting on connecting rod risk of fretting corrosion or wear You
bearings) are considered to be rotating should use an interference it for both
loads rings The same it as for a rotating load is
normally suitable Where the outer ring
B.6 Bearing interfaces

Table 1

Conditions of rotation

Operating conditions Schematic illustration Load condition Recommended its

Rotating inner ring Rotating inner ring load Interference it for the inner ring
Stationary outer ring Stationary outer ring load Loose it for the outer ring possible
Constant load direction

Rotating inner ring Stationary inner ring load Loose it for the inner ring possible
Stationary outer ring Rotating outer ring load Interference it for the outer ring
Load rotates with the inner ring

Stationary inner ring Stationary inner ring load Loose it for the inner ring possible
Rotating outer ring Rotating outer ring load Interference it for the outer ring
Constant load direction

Stationary inner ring Rotating inner ring load Interference it for the inner ring
Rotating outer ring Stationary outer ring load Loose it for the outer ring possible
Load rotates with outer ring

142
 Selecting its

Magnitude of load Precision Ease of mounting

The ring of a bearing deforms proportion- requirements and dismounting
ately to the load For rotating inner ring
loads, this deformation can loosen the inter- To minimize delections and vibration in pre- Loose its are beneicial for easy mounting
ference it between the inner ring and shaft, cision or high-speed applications, interfer- and dismounting In applications where
causing the ring to creep on its shaft seat ence or transition its are recommended interference its are required for both the
The heavier the load, the tighter the inter- shaft and housing seat, separable bearings
ference it required The required interfer- or bearings with a tapered bore should be
ence can be estimated using: considered Bearings with a tapered bore
Design and material can be mounted on tapered sleeves (ig. 2)
JKK or on a tapered shaft seat (ig. 3)
∆ = 2,5PFr K
d
B of the shaft and
where
housing
Δ = required interference [µm] Distortion of the bearing rings caused by Axial displacement of
d = bearing bore diameter [mm] shaft or housing design, for example by dis-
B = bearing width [mm] continuities of the seat or uneven wall thick- the bearing in the
Fr = radial load [kN] ness, should be avoided
For split housings, SKF generally recom-
non-locating position
Where sudden load peaks or vibration mends loose its The tighter (less loose) the When a non-locating bearing needs to be
occurs, a tighter it can be required it is in a split housing, the higher are the able to move axially on its seat, the ring sub-
requirements for the geometrical tolerances jected to the stationary load should have a
of the seat Split housings machined to tight loose it For additional information about
tolerances, such as SKF plummer block bearings in the non-locating position, refer
Temperature housings, can be used for transition its up to to Arrangements and their bearing
K7 types, page 70
differences Bearings mounted in thin-walled hous-
ings or on hollow shafts require tighter

B.6 Bearing interfaces

In operation, bearing rings normally reach a interference its than those recommended
temperature that is higher than that of the for robust cast iron housings or solid shafts
components to which they are itted This (Tolerances for seats on hollow shafts,
can loosen the it on the shaft seat, while page 146)
outer ring expansion can prevent the desired Shafts or housings made of materials
axial displacement in the housing other than steel or cast iron may require
Rapid start-up can loosen the inner ring different its depending on material strength
it when the frictional heat generated by the and thermal properties
bearing is not dissipated quickly enough In
some cases, friction from seals can generate
enough heat to loosen the inner ring it
External heat and the direction of heat
low can have an effect on its Steady-state
and transient conditions must be considered
For additional information about tempera-
ture differences, refer to Selecting internal
clearance or preload, page 182 Fig. 2 Fig. 3

Bearing with a tapered bore mounted on a Bearing with a tapered bore mounted on a
plain shaft with an adapter sleeve tapered seat

143
 B.6 Bearing interfaces

Tolerances for typically machined to the following

tolerances:
tolerances are permissible The total run-out
tolerances should be the same as for bear-
bearing seats and • shaft seats to grade IT6 dimensional toler-
ings on cylindrical seats
Tolerance values for ISO tolerance grades
abutments ances and grade IT5 total run-out
tolerances
are listed in table 3

• housing seats to grade IT7 dimensional

Dimensional tolerances for bearing seats are tolerances and grade IT6 total run-out
dictated by the required it Precision tolerances
requirements of the application will direct
you to which bearing tolerance class to use Suitable combinations of tolerance grades
(Bearing execution, page 182) and, conse- are listed in table 2 The tolerance zone for
quently, what run-out tolerance of the seat the total radial run-out is limited to half of
is needed The run-out of the seat is speci- the ISO tolerance grade, because the run-
ied by the total radial run-out of the seat out tolerance is speciied as a difference in
surface and the total axial run-out of the radii of two coaxial cylinders, and the ISO
abutment (ISO 1101, 18 16) tolerance grade refers to the diameter
For bearings with Normal tolerances in For seats of bearings mounted on with-
general industrial applications, seats are drawal or adapter sleeves, wider diameter

Table 2

Tolerance grades for bearing seats1)

Application requirements Shaft seat Housing seat

A B
t2 A-B
t1 A-B
A B
B.6 Bearing interfaces

dA dB DA DB

t2 A-B
t1 A-B

Dimensional Geometrical tolerance grades Dimensional Geometrical tolerance grades

tolerance tolerance
grade grade

Radial run-out Axial run-out Radial run-out Axial run-out

t1 t2 t1 t2

Bearing to Normal tolerances IT6 IT5/2 IT5 IT7 IT6/2 IT6

(moderate speed and running
accuracy)

Bearing to P6 tolerances IT5 IT4/2 IT4 IT6 IT5/2 IT5

(higher speeds or running
accuracy)

Bearing to P5 tolerances IT4 IT3/2 IT3 IT5 IT4/2 IT4

(high speeds and running
accuracy)

1) For very high-speed and high-precision applications, use SKF super-precision bearings and reduced IT tolerances (skf com/super-precision)

144
 Tolerances for bearing seats and abutments

Example Fig. 4
A deep groove ball bearing 6030 is to be Dimensional and total run-out tolerances zones
used in an electric motor The bearing
accommodates normal to heavy loads
(0,05 C < P ≤ 0,1 C), and requirements for
speed and precision are moderate An inter-
ference it on the shaft is required For this
it, the shaft diameter should be 150 m6�
The total radial run-out should be within 150,040 150,015
IT5/2 (from table 3: 18/2 = 9 µm), and the
total axial run-out of the abutment should
0,009
be within IT5 (from table 3: 18 µm)
The dimensional tolerance zone in grey
and the tolerance zone for the total radial Dimensional tolerance: 150 m6�
run-out in blue are shown in ig. 4 The blue Total radial run-out 9 µm
Actual dimensions of the shaft seat
zone can be located at any place within the
grey zone, but must not be wider than 9 µm

Table 3

Values of ISO tolerance grades

Nominal Tolerance grades

B.6 Bearing interfaces

dimension IT3 IT4 IT5 IT6 IT7 IT8 IT9
> ≤ max.

mm µm

1 3 2 3 4 6 10 14 25
3 6 3 4 5 8 12 18 30
6 10 3 4 6 9 15 22 36

10 18 3 5 8 11 18 27 43
18 30 4 6 9 13 21 33 52
30 50 4 7 11 16 25 39 62

50 80 5 8 13 19 30 46 74
80 120 6 10 15 22 35 54 87
120 180 8 12 18 25 40 63 100

180 250 10 14 20 29 46 72 115

250 315 12 16 23 32 52 81 130
315 400 13 18 25 36 57 89 140

400 500 15 20 27 40 63 97 155

500 630 - - 32 44 70 110 175
630 800 - - 36 50 80 125 200

800 1 000 - - 40 56 90 140 230

1 000 1 250 - - 47 66 105 165 260
1 250 1 600 - - 55 78 125 195 310

1 600 2 000 - - 65 92 150 230 370

2 000 2 500 - - 78 110 175 280 440

145
 B.6 Bearing interfaces

Tolerances for seats For shaft diameter ratios ci > 0,5 the diam- • The diameter ratio of the bearing inner
eter tolerance determined for a seat on a ring is
on hollow shafts solid shaft should be adjusted to achieve the
same effectiveness of the it on the hollow
40
When a bearing is mounted on a hollow shaft This can be done with the following ce = JJJJJJJL = 0,77
shaft using an interference it, the shaft procedure 0,3 (80 – 40) + 40
experiences more elastic deformation than a
solid shaft As a result, the effectiveness of 1 Determine the mean probable interfer- • The mean probable interference on a solid
the it is less than for the same size solid ence for the tolerance selected for a seat shaft is
shaft The effectiveness of an interference it on a solid shaft, ΔS (Tolerances and result- ΔS = (22 + 5) / 2 = 13,5 μm (table 14,
on a hollow shaft depends on certain diam- ant fits, page 153) page 160 , k5 for a 40 mm shaft
eter ratios (ig. 5): 2 Determine the required increase of inter- diameter)
ference for the seat on the hollow shaft
• the diameter ratio of the hollow shaft from diagram 1, based on the diameter • The increase in interference for the seat
ci = di / d ratios ci and ce on the hollow shaft is
For diameter ratios ci ≤ 0,5 the reduc- 3 Calculate the required mean probable ΔH / ΔS = 1,7 (diagram 1, ci = 0,8 and
tion of effectiveness is negligible interference for the seat on the hollow ce = 0,77)
• the diameter ratio of the bearing inner shaft and select the tolerance class
ring ce = d / de accordingly • The requisite interference for the seat on
When the average outside diameter of the hollow shaft is
the inner ring de is not known, the diam- Example ΔH = 1,7 × 13,5 = 23 μm
eter ratio can be estimated from
A 6208 deep groove ball bearing with • The appropriate tolerance class for the
d = 40 mm and D = 80 mm is to be mounted seat on the hollow shaft is m6 (table 14,
d
ce = JJJJJ on a hollow shaft with a diameter ratio mean probable interference,
k (D – d) + d ci = 0,8 What is the appropriate tolerance (33 + 13) / 2 = 23 μm)
class for the shaft seat?
The bearing is subjected to normal loads,
where and a tolerance class k5 is appropriate for a
B.6 Bearing interfaces

ce = diameter ratio of the bearing inner seat on a solid shaft

ring
d = bearing bore diameter [mm]
D = bearing outside diameter [mm]
k = adjustment factor
= 0,25 for self-aligning ball bearings in
the 22 and 23 series
= 0,25 for cylindrical roller bearings
= 0,3 for other bearings

Diagram 1

Relationship of interference ΔH, needed for a hollow steel shaft, to the known interference ΔS
for a solid steel shaft

Fig. 5
ΔH / ΔS
Seat on a hollow shaft 2,0

1,8
ce = 0,7
1,6

1,4
di d de 0,8
1,2
0,9
1,0
0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9
ci

146
 Surface texture of bearing seats

Tolerances for • The roundness tolerance is deined as Surface texture of

“distance t between two concentric circles
tapered seats in each radial plane along the tapered sur- bearing seats
face of the shaft” t is the value of tolerance
For tapered shaft seats, SKF recommends grade IT5/2, based on the diameter d
the following tolerances (ig. 6): Where a high degree of precision is The surface texture of a bearing seat has
required, IT4/2 should be used instead less of an impact on bearing performance
• The permissible deviation for the slope of • The straightness is deined as “In each compared to the dimensional and geomet-
the taper is a ± tolerance in accordance axial plane through the tapered shaft, the rical tolerances of the seat However, the
with IT7/2 The bearing width B is the tolerance zone is limited by two parallel texture of the mating surfaces affects
nominal size, which determines the stand- lines a distance t apart” t is the value of smoothing, which can reduce the interfer-
ard tolerance values The permissible tolerance grade IT5/2, based on the diam- ence in a it The surface texture should be
deviation for the slope of the taper can be eter d limited to ensure the required it is obtained
determined using Guideline values for the roughness proile
parameter Ra are listed in table 4 These
Taper position recommendations apply to ground seats,
∆k = ❏❏
IT7/2
B
which are normally assumed for shaft seats
Only dimensional and geometrical toler- For housing seats, which are normally ine-
ances of the taper are indicated in ig. 6 The turned, the Ra values may be one class
The permissible range of dispersion of the axial position of the taper requires additional higher For applications where some loss of
slope of the taper can be determined speciications When specifying the axial interference is not critical, rougher surfaces
using position, you should also take into account than recommended in table 4 can be used
the axial drive-up distance of the bearing,
which is required to achieve a suitable inter-
Vk = 1/k ± ❏❏
IT7/2
B
ference it

Checking tolerances
where

B.6 Bearing interfaces

Δk = the permissible deviation of the To check whether a tapered shaft seat is
slope of the taper within its tolerances, SKF recommends
Vk = the permissible range of dispersion measuring it with a special taper gauge,
of the slope of the taper based on saddles and gauging pins More
B = bearing width [mm] practical, but less accurate measurement
IT7 = the value of the tolerance grade, methods include ring gauges, taper gauges
based on the bearing width [mm] and sine bars For information about SKF
k = factor for the taper measuring devices, refer to skf com (GRA 30
= 12 for taper 1:12 ring gauges and DMB taper gauges)
= 30 for taper 1:30

Table 4 Fig. 6

Surface roughness of bearing seats Tolerances for tapered shaft seats

Seat diameter Ra (guideline values for ground seats) 1/k ± (IT7/2) / B

d, D Diameter tolerance grade IT5/2 A t

> ≤ IT7 IT6 IT5 Ra 1,6 IT5/2
A
mm μm

– 80 1,6 0,8 0,4

80 500 1,6 1,6 0,8
500 1 250 3,21) 1,6 1,6
d js9 E
t

1) When using the oil injection method for mounting, Ra should not exceed 1,6 μm B

147
 B.6 Bearing interfaces

Seat tolerances • For solid steel shafts:

– Radial ball bearings (table 5, except
All ISO tolerance classes used in the tables
are valid with the envelope requirement
for standard insert bearings)
– Radial roller bearings (table 6, except
(such as H7�), in accordance with
ISO 14405-1 For practical reasons, symbol
conditions needle roller bearings)
– Thrust ball bearings and spherical roller
� is not indicated in the tables

thrust bearings (table 7, page 150)

The following tables provide recommenda- • For cast iron and steel housings:
tions for tolerances of shaft and housing – Radial bearings (table 8, page 151)
seats They are valid for standard applica- – Thrust bearings (table 9, page 152)
tions but do not cover all details of a speciic
application The information under For the following bearing types, recommen-
Selecting fits, page 140, and Tolerances for dations are listed in the product sections:
bearing seats and abutments, page 144,
should be additionally considered • Insert bearings, Design considerations,
These recommendations are valid for page 356
bearings with Normal dimensional toler- • Needle roller bearings, relevant sections
ances They can also be used for bearings to under Needle roller bearings, page 903
P6 dimensional tolerances The tighter P6 • Cylindrical roller thrust bearings, Design
tolerance zone changes the resulting it only considerations, page 885
slightly • Needle roller thrust bearings, Design
Recommended seat tolerances for metric considerations, page 903
bearings: • Inch tapered roller bearings, Design
considerations, page 687

Table 5

Tolerances for solid steel shafts – seats for radial ball bearings1)

Conditions Shaft diameter Dimensional tolerance2) Total radial run-out Total axial run-out Ra
B.6 Bearing interfaces

tolerance3) tolerance3)

mm – – – µm

Rotating inner ring load or direction of load indeterminate

Light loads (P ≤ 0,05 C) ≤ 17 js5 IT4/2 IT4 0,4
> 17 to 100 j6 IT5/2 IT5 0,8
> 100 to 140 k6 IT5/2 IT5 1,6

Normal to heavy loads ≤ 10 js5 IT4/2 IT4 0,4

(0,05 C < P ≤ 0,1 C) > 10 to 17 j5 IT4/2 IT4 0,4
> 17 to 100 k5 IT4/2 IT4 0,8

> 100 to 140 m5 IT4/2 IT4 0,8

> 140 to 200 m6 IT5/2 IT5 1,6
> 200 to 500 n6 IT5/2 IT5 1,6

> 500 p7 IT6/2 IT6 3,2

Stationary inner ring load

Easy axial displacement of inner ring on shaft g64) IT5/2 IT5 1,6
desirable
Easy axial displacement of inner ring on shaft h6 IT5/2 IT5 1,6
unnecessary

Axial loads only j6 IT5/2 IT5 1,6

1) For insert bearings, refer to Design considerations, page 356

2) The envelope requirement (symbol � from ISO 14405-1) is not shown but applies to all tolerance classes
3) Values listed are for bearings to Normal tolerances For bearings with tighter tolerance classes, use the recommendations in table 2, page 144
4) Depending on bearing size, a shifted g6� tolerance may be needed to obtain a loose it

148
 Seat tolerances for standard conditions

Bearings with a • Self-aligning ball bearings, page 438

• Spherical roller bearings, page 774
tapered bore • CARB toroidal roller bearings, page 842

Bearings with a tapered bore are always For seats of bearings mounted on tapered
mounted with an interference it for the sleeves, wider diameter tolerances are per-
inner ring The it is determined by the dis- missible The total run-out tolerances should
tance through which the inner ring is driven be the same as for bearings on cylindrical
up on a tapered seat or sleeve For detailed seats (Tolerances for bearing seats and abut-
information, refer to the information in the ments, page 144)
product sections: Suitable tolerances are listed in table 10,
page 152 They are valid for moderate
speeds and moderate precision
requirements

Table 6

Tolerances for solid steel shafts – seats for radial roller bearings1)
Conditions Shaft diameter Dimensional tolerance2) Total radial run-out Total axial run-out Ra
tolerance3) tolerance3)

mm – – – µm

Rotating inner ring load or direction of load indeterminate

Light loads (P ≤ 0,05 C) ≤ 25 j6 IT5/2 IT5 0,8
> 25 to 60 k6 IT5/2 IT5 0,8
> 60 to 140 m6 IT5/2 IT5 0,8

Normal to heavy loads ≤ 30 k6 IT5/2 IT5 0,8

(0,05 C < P ≤ 0,1 C) > 30 to 50 m5 IT5/2 IT5 0,8
> 50 to 65 n5 IT5/2 IT5 0,8

> 65 to 100 n6 IT5/2 IT5 0,8

B.6 Bearing interfaces

> 100 to 280 p6 IT5/2 IT5 1,6
> 280 to 500 r6 IT5/2 IT5 1,6

> 500 r7 IT6/2 IT6 3,2

Heavy to very heavy > 50 to 65 n5 IT5/2 IT5 0,8

loads and high peak > 65 to 85 n6 IT5/2 IT5 0,8
loads under dificult > 85 to 140 p6 IT5/2 IT5 0,8
operating conditions
(P > 0,1 C) > 140 to 300 r6 IT5/2 IT5 1,6
> 300 to 500 r6 + IT64) IT5/2 IT5 1,6
> 500 r7 + IT74) IT6/2 IT6 3,2

Stationary inner ring load

Easy axial displacement of inner ring on shaft g65) IT5/2 IT5 1,6
desirable
Easy axial displacement of inner ring on shaft h6 IT5/2 IT5 1,6
unnecessary

Axial loads only j6 IT5/2 IT5 1,6

1) For needle roller bearings, refer to the relevant sections under Needle roller bearings, page 581
2) The envelope requirement (symbol � from ISO 14405-1) is not shown but applies to all tolerance classes
3) Values listed are for bearings to Normal tolerances For bearings with tighter tolerance classes, use the recommendations in table 2, page 144
4) Shifted tolerance ield

r7 max + IT7
r6 max + IT6

IT6 IT7
r6 max r7 max
r6 min + IT6 r7 min + IT7
IT6 IT7
r6 min 1) 2)
r7 min

5) Depending on bearing size, a shifted g6� tolerance may be needed to obtain a loose it

149
 B.6 Bearing interfaces

Table 7

Tolerances for solid steel shafts – seats for thrust bearings1)

Conditions Shaft diameter Dimensional tolerance2) Total radial run-out Total axial run-out Ra
tolerance tolerance

mm – – – µm

Axial loads only on thrust ball bearings

h6 IT5/2 IT5 1,63)

Combined radial and axial loads on spherical roller thrust bearings

Stationary load on shaft all j6 IT5/2 IT5 1,63)
washer

Rotating load on shaft ≤ 200 k6 IT5/2 IT5 1,63)

washer, or direction of
oad indeterminate > 200 to 400 m6 IT5/2 IT5 1,6

> 400 n6 IT5/2 IT5 1,6

1) For cylindrical roller thrust bearings, refer to Design considerations, page 885 For needle roller thrust bearings, refer to Design considerations, page 903
2) The envelope requirement (symbol � from ISO 14405-1) is not shown but applies to all tolerance classes
3) For d ≤ 80 mm, use Ra = 0,8 µm
B.6 Bearing interfaces

150
 Seat tolerances for standard conditions

Table 8

Tolerances for cast iron and steel housings – seats for radial bearings1)

Conditions Dimensional Total radial run-out Total axial run-out Ra6) Displacement of
tolerance2)3) tolerance tolerance outer ring

– – – µm –

For non-split Rotating outer ring load

housings only
Heavy loads on bearings in P7 IT6/2 IT6 3,2 Cannot be
thin-walled housings, displaced
heavy peak loads (P > 0,1 C)

Normal to heavy loads N7 IT6/2 IT6 3,2 Cannot be

(P > 0,05 C) displaced

Light and variable loads M7 IT6/2 IT6 3,2 Cannot be

(P ≤ 0,05 C) displaced

Direction of load indeterminate

Heavy peak loads M7 IT6/2 IT6 3,2 Cannot be

displaced

Normal to heavy loads K75) IT6/2 IT6 3,2 In most cases,

(P > 0,05 C), axial displace- cannot be
ment of outer ring displaced
unnecessary

For non-split Direction of load indeterminate

housings and split

B.6 Bearing interfaces

housings
Light to normal loads J7 IT6/2 IT6 3,2 In most cases, can
(P ≤ 0,1 C), axial displace- be displaced
ment of outer ring desirable

Stationary outer ring load

Loads of all kinds H73) IT6/2 IT6 3,2 Can be displaced

Light to normal loads H83) IT6/2 IT6 3,2 Can be displaced

(P ≤ 0,1 C) with simple work-
ing conditions

Thermal expansion of the G74) IT6/2 IT6 3,2 Can be displaced

shaft

1) For drawn cup, alignment and combined needle roller bearings, refer to Shaft and housing tolerances, page 610
2) The envelope requirement (symbol � from ISO 14405-1) is not shown but applies to all tolerance classes
3) For large bearings (D > 250 mm), or temperature differences between the outer ring and housing > 10 °C (18 °F), tolerance class G7� should be used
instead of tolerance class H7�
4) For large bearings (D > 500 mm), or temperature differences between the outer ring and housing > 10 °C (18 °F), tolerance class F7� should be used instead of tolerance class G7�
5) A split housing is allowed provided housing halves are well aligned during machining of the housing, with relief chamfers at the split
6) For D > 500 mm, use Ra = 6,3 µm

151
 B.6 Bearing interfaces

Table 9

Tolerances for cast iron and steel housings – seats for thrust bearings1)

Conditions Dimensional Total axial run-out Ra Remarks

tolerance2) tolerance

– – µm –

Axial loads only

Thrust ball bearings H8 IT7 6,3 For less precise bearing arrangements, there
can be a radial clearance of up to 0,001 D

Spherical roller thrust bearings where – IT6 Housing washer must be itted with an ade-
separate bearings provide radial location quate radial gap so that no radial load can act
on the thrust bearings
Combined radial and axial loads on
spherical roller thrust bearings

Stationary load on housing washer H7 IT6 3,23) For additional information, refer to Design
arrangements considerations, page 918

Rotating load on housing washer

M7 IT6 3,23)

1) For cylindrical roller thrust bearings, refer to Design considerations, page 885 For needle roller thrust bearings, refer to Design considerations, page 903
2) The envelope requirement (symbol � from ISO 14405-1) is not shown but applies to all tolerance classes
3) For D < 80 mm, use Ra = 1,6 µm
B.6 Bearing interfaces

Table 10

Tolerances for seats of bearings mounted on tapered sleeves

Shaft diameter Diameter tolerance Total radial

run-out
d
Nominal h9� IT5/2
> ≤ U L max.

mm µm mm

10 18 0 -43 4
18 30 0 -52 5
30 50 0 -62 6

50 80 0 -74 7
80 120 0 -87 8
120 180 0 -100 9

180 250 0 -115 10

250 315 0 -130 12
315 400 0 -140 13

400 500 0 -155 14

500 630 0 -175 16
630 800 0 -200 18

800 1 000 0 -230 20

1 000 1 250 0 -260 24

152
 Tolerances and resultant its

Tolerances and
resultant fits
The tables in this section provide informa-
tion about bearing tolerances, seat toler-
ances and resultant its (ig. 7) These should
enable you to determine easily the max-
imum and minimum values of its when
using ISO tolerance classes for bearing seats
and bearings with Normal tolerances for the
bore and outside diameter The SKF Bearing
Calculator (skf com/bearingcalculator) pro-
vides a similar function for every individual
bearing
The tables cannot be used for tapered
roller bearings when d ≤ 30 mm or
D ≤ 150 mm or for thrust bearings when
D ≤ 150 mm The diameter tolerances for
these bearings deviate from the Normal tol-
erances for other rolling bearings

The tables list:

• the upper and lower limits of bore or out-

side diameter deviations for bearings with
Normal tolerances
• the upper and lower limits of shaft or

B.6 Bearing interfaces

housing bore diameter deviations for rele-
vant tolerance classes in accordance with
ISO 2862
• the smallest and largest values of the the-
oretical interference (–) or clearance (+)
• the smallest and largest values of the ±3σ
probable interference (–) or clearance (+) Fig. 7

Shaft and housing tolerances and resultant its

The appropriate values for shaft seats are
listed for the following tolerance classes:

• f5, f6, g5, g6, h5 (table 11, page 154)

• h6, h8, h9, j5, j6 (table 12, page 156) Minimum Maximum
• js4, js5, js6, js7, k4 (table 13, page 158) clearance in clearance in
the housing the housing
• k5, k6, m5, m6, n5 (table 14, page 160)
• n6, p6, p7, r6, r7 (table 15, page 162)
• r6+IT6, r7+IT7 (table 16, page 164)
Minimum Maximum
interference interference
The appropriate values for housing seats are on the shaft on the shaft
listed for the following tolerance classes:

• F7, G6, G7, H5, H6 (table 17, page 166)

• H7, H8, H9, H10, J6 (table 18, page 168)
• J7, JS5, JS6, JS7, K5 (table 19, page 170)
• K6, K7, M5, M6, M7 (table 20, page 172)
• N6, N7, P6, P7 (table 21, page 174)
Tolerance intervals Tolerance interval Tolerance interval
of the bearing bore of the housing seat of the shaft seat
and outside diameter

153
 B.6 Bearing interfaces

Table 11

Shaft tolerances and resultant its

+
0
–

Shaft Bearing Shaft diameter deviations, resultant its1)

Normal Bore diameter Tolerance classes
diameter tolerance
d tΔdmp f5� f6� g5� g6� h5�

Deviations (shaft diameter)

Theoretical interference (–)
over incl low high Probable interference (–)

mm µm µm

– 3 –8 0 –6 –10 –6 –12 –2 –6 –2 –8 0 –4
–2 +10 –2 +12 –6 +6 –6 +8 –8 +4
–1 +9 0 +10 –5 +5 –4 +6 –7 +3

3 6 –8 0 –10 –15 –10 –18 –4 –9 –4 –12 0 –5

+2 +15 +2 +18 –4 +9 –4 +12 –8 +5
+3 +14 +4 +16 –3 +8 –2 +10 –7 +4

6 10 –8 0 –13 –19 –13 –22 –5 –11 –5 –14 0 –6

+5 +19 +5 +22 –3 +11 –3 +14 –8 +6
+7 +17 +7 +20 –1 +9 –1 +12 –6 +4

10 18 –8 0 –16 –24 –16 –27 –6 –14 –6 –17 0 –8

+8 +24 +8 +27 –2 +14 –2 +17 –8 +8
+10 +22 +10 +25 0 +12 0 +15 –6 +6

18 30 –10 0 –20 –29 –20 –33 –7 –16 –7 –20 0 –9

+10 +29 +10 +33 –3 +16 –3 +20 –10 +9
B.6 Bearing interfaces

+12 +27 +13 +30 –1 +14 0 +17 –8 +7

30 50 –12 0 –25 –36 –25 –41 –9 –20 –9 –25 0 –11

+13 +36 +13 +41 –3 +20 –3 +25 –12 +11
+16 +33 +17 +37 0 +17 +1 +21 –9 +8

50 80 –15 0 –30 –43 –30 –49 –10 –23 –10 –29 0 –13
+15 +43 +15 +49 –5 +23 –5 +29 –15 +13
+19 +39 +19 +45 –1 +19 –1 +25 –11 +9

80 120 –20 0 –36 –51 –36 –58 –12 –27 –12 –34 0 –15
+16 +51 +16 +58 –8 +27 –8 +34 –20 +15
+21 +46 +22 +52 –3 +22 –2 +28 –15 +10

120 180 –25 0 –43 –61 –43 –68 –14 –32 –14 –39 0 –18
+18 +61 +18 +68 –11 +32 –11 +39 –25 +18
+24 +55 +25 +61 –5 +26 –4 +32 –19 +12

180 250 –30 0 –50 –70 –50 –79 –15 –35 –15 –44 0 –20
+20 +70 +20 +79 –15 +35 –15 +44 –30 +20
+26 +64 +28 +71 –9 +29 –7 +36 –24 +14

250 315 –35 0 –56 –79 –56 –88 –17 –40 –17 –49 0 –23
+21 +79 +21 +88 –18 +40 –18 +49 –35 +23
+29 +71 +30 +79 –10 +32 –9 +40 –27 +15

315 400 –45 0 –62 –87 –62 –98 –18 –43 –18 –54 0 –25
+22 +87 +22 +98 –22 +43 –22 +54 –40 +25
+30 +79 +33 +87 –14 +35 –11 +43 –32 +17

400 500 –45 0 –68 –95 –68 –108 –20 –47 –20 –60 0 –27
+23 +95 +23 +108 –25 +47 –25 +60 –45 +27
+32 +86 +35 +96 –16 +38 –13 +48 –36 +18

500 630 –50 0 –76 –104 –76 –120 –22 –50 –22 –66 0 –28
+26 +104 +26 +120 –28 +50 –28 +66 –50 +28
+36 +94 +39 +107 –18 +40 –15 +53 –40 +18

154
 Tolerances and resultant its

Table 11

Shaft tolerances and resultant its

+
0
–

Shaft Bearing Shaft diameter deviations, resultant its1)

Nominal Bore diameter Tolerance classes
diameter tolerance
d tΔdmp f5� f6� g5� g6� h5�

Deviations (shaft diameter)

Theoretical interference (–)
over incl low high Probable interference (–)

mm µm µm

630 800 –75 0 –80 –112 –80 –130 –24 –56 –24 –74 0 –32
+5 +112 +5 +130 –51 +56 –51 +74 –75 +32
+17 +100 +22 +113 –39 +44 –34 +57 –63 +20

800 1 000 –100 0 –86 –122 –86 –142 –26 –62 –26 –82 0 –36
–14 +122 –14 +142 –74 +62 –74 +82 –100 +36
0 +108 +6 +122 –60 +48 –54 +62 –86 +22

1 000 1 250 –125 0 –98 –140 –98 –164 –28 –70 –28 –94 0 –42
–27 +140 –27 +164 –97 +70 –97 +94 –125 +42
–10 +123 –3 +140 –80 +53 –73 +70 –108 +25

1 250 1 600 –160 0 –110 –160 –110 –188 –30 –80 –30 –108 0 –50
–50 +160 –50 +188 –130 +80 –130 +108 –160 +50
–29 +139 –20 +158 –109 +59 –100 +78 –139 +29

1 600 2 000 –200 0 –120 –180 –120 –212 –32 –92 –32 –124 0 –60
–80 +180 –80 +212 –168 +92 –168 +124 –200 +60

B.6 Bearing interfaces

–55 +155 –45 +177 –143 +67 –133 +89 –175 +35

1) Values are valid for most bearings with Normal tolerances For exceptions, refer to Tolerances and resultant fits, page 153

155
 B.6 Bearing interfaces

Table 12

Shaft tolerances and resultant its

+
0
–

Shaft Bearing Shaft diameter deviations, resultant its1)

Normal Bore diameter Tolerance classes
diameter tolerance
d tΔdmp h6� h8� h9� j5� j6�

Deviations (shaft diameter)

Theoretical interference (–)/clearance (+)
> ≤ L U Probable interference (–)/clearance (+)

mm µm µm

– 3 –8 0 0 –6 0 –14 0 –25 +2 –2 +4 –2
–8 +6 –8 +14 –8 +25 –10 +2 –12 +2
–6 +4 –6 +12 –5 +22 –9 +1 –10 0

3 6 –8 0 0 –8 0 –18 0 –30 +3 –2 +6 –2
–8 +8 –8 +18 –8 +30 –11 +2 –14 +2
–6 +6 –5 +15 –5 +27 –10 +1 –12 0

6 10 –8 0 0 –9 0 –22 0 –36 +4 –2 +7 –2
–8 +9 –8 +22 –8 +36 –12 +2 –15 +2
–6 +7 –5 +19 –5 +33 –10 0 –13 0

10 18 –8 0 0 –11 0 –27 0 –43 +5 –3 +8 –3

–8 +11 –8 +27 –8 +43 –13 +3 –16 +3
–6 +9 –5 +24 –5 +40 –11 +1 –14 +1

18 30 –10 0 0 –13 0 –33 0 –52 +5 –4 +9 –4

–10 +13 –10 +33 –10 +52 –15 +4 –19 +4
B.6 Bearing interfaces

–7 +10 –6 +29 –6 +48 –13 +2 –16 +1

30 50 –12 0 0 –16 0 –39 0 –62 +6 –5 +11 –5

–12 +16 –12 +39 –12 +62 –18 +5 –23 +5
–8 +12 –7 +34 –7 +57 –15 +2 –19 +1

50 80 –15 0 0 –19 0 –46 0 –74 +6 –7 +12 –7

–15 +19 –15 +46 –15 +74 –21 +7 –27 +7
–11 +15 –9 +40 –9 +68 –17 +3 –23 +3

80 120 –20 0 0 –22 0 –54 0 –87 +6 –9 +13 –9

–20 +22 –20 +54 –20 +87 –26 +9 –33 +9
–14 +16 –12 +46 –12 +79 –21 +4 –27 +3

120 180 –25 0 0 –25 0 –63 0 –100 +7 –11 +14 –11

–25 +25 –25 +63 –25 +100 –32 +11 –39 +11
–18 +18 –15 +53 –15 +90 –26 +5 –32 +4

180 250 –30 0 0 –29 0 –72 0 –115 +7 –13 +16 –13

–30 +29 –30 +72 –30 +115 –37 +13 –46 +13
–22 +21 –18 +60 –17 +102 –31 +7 –38 +5

250 315 –35 0 0 –32 0 –81 0 –130 +7 –16 +16 –16

–35 +32 –35 +81 –35 +130 –42 +16 –51 +16
–26 +23 –22 +68 –20 +115 –34 +8 –42 +7

315 400 –40 0 0 –36 0 –89 0 –140 +7 –18 +18 –18

–40 +36 –40 +89 –40 +140 –47 +18 –58 +18
–29 +25 –25 +74 –23 +123 –39 +10 –47 +7

400 500 –45 0 0 –40 0 –97 0 –155 +7 –20 +20 –20

–45 +40 –45 +97 –45 +155 –52 +20 –65 +20
–33 +28 –28 +80 –26 +136 –43 +11 –53 +8

156
 Tolerances and resultant its

Table 12

Shaft tolerances and resultant its

+
0
–

Shaft Bearing Shaft diameter deviations, resultant its1)

Normal Bore diameter Tolerance classes
diameter tolerance
d tΔdmp h6� h8� h9� j5� j6�

Deviations (shaft diameter)

Theoretical interference (–)/clearance (+)
> ≤ L U Probable interference (–)/clearance (+)

mm µm µm

500 630 –50 0 0 –44 0 –110 0 –175 – – –22 –22

–50 +44 –50 +110 –50 +175 – – –72 +22
–37 +31 –31 +91 –29 +154 – – –59 +9

630 800 –75 0 0 –50 0 –125 0 –200 – – +25 –25

–75 +50 –75 +125 –75 +200 – – –100 +25
–58 +33 –48 +98 –45 +170 – – –83 +8

800 ✶ ✚✚✚ –100 0 0 –56 0 –140 0 –230 – – +28 –28

–100 +56 –100 +140 –100 +230 – – –128 +28
–80 +36 –67 +107 –61 +191 – – –108 +8

✶ ✚✚✚ ✶ ✛✜✚ –125 0 0 –66 0 –165 0 –260 – – +33 –33

–125 +66 –125 +165 –125 +260 – – –158 +33
–101 +42 –84 +124 –77 +212 – – –134 +9

✶ ✛✜✚ ✶ ✢✚✚ –160 0 0 –78 0 –195 0 –310 – – +39 –39

–160 +78 –160 +195 –160 +310 – – –199 +39

B.6 Bearing interfaces

–130 +48 –109 +144 –100 +250 – – –169 +9

✶ ✢✚✚ ✛ ✚✚✚ –200 0 0 –92 0 –230 0 –370 – – +46 –46

–200 +92 –200 +230 –200 +370 – – –246 +46
–165 +57 –138 +168 –126 +296 – – –211 +11

1) Values are valid for most bearings with Normal tolerances For exceptions, refer to Tolerances and resultant fits, page 153

157
 B.6 Bearing interfaces

Table 13

Shaft tolerances and resultant its

+
0
–

Shaft Bearing Shaft diameter deviations, resultant its1)

Nominal diameter Bore diameter Tolerance classes
tolerance
d tΔdmp js4� js5� js6� js7� k4�

Deviations (shaft diameter)

Theoretical interference (–)/clearance (+)
over incl low high Probable interference (–)/clearance (+)

mm µm µm

– 3 –8 0 +1,5 –1,5 +2 –2 +3 –3 +5 –5 +3 0
–9,5 +1,5 –10 +2 –11 +3 –13 +5 –11 0
–8,5 +0,5 –9 +1 –9 +1 –11 +3 –10 –1

3 6 –8 0 +2 –2 +2,5 –2,5 +4 –4 +6 –6 +5 +1
–10 +2 –10,5 +2,5 –12 +4 –14 +6 –13 –1
–9 +1 –9 +1 –10 +2 –12 +4 –12 –2

6 10 –8 0 +2 –2 +3 –3 +4,5 –4,5 +7,5 –7,5 +5 +1

–10 +2 –11 +3 –12,5 +4,5 –15,5 +7,5 –13 –1
–9 +1 –9 +1 –11 +3 –13 +5 –12 –2

10 18 –8 0 +2,5 –2,5 +4 –4 +5,5 –5,5 +9 –9 +6 +1

–10,5 +2,5 –12 +4 –13,5 +5,5 –17 +9 –14 –1
–9,5 +1,5 –10 +2 –11 +3 –14 +6 –13 –2

18 30 –10 0 +3 –3 +4,5 –4,5 +6,5 –6,5 +10,5 –10,5 +8 +2

–13 +3 –14,5 +4,5 –16,5 +6,5 –20,5 +10,5 –18 –2
B.6 Bearing interfaces

–10,5 +1,5 –12 +2 –14 +4 –17 +7 –16 –4

30 50 –12 0 +3,5 –3,5 +5,5 –5,5 +8 –8 +12,5 –12,5 +9 +2

–15,5 +3,5 –17,5 +5,5 –20 +8 –24,5 +12,5 –21 –2
–13,5 +1,5 –15 +3 –16 +4 –20 +8 –19 –4

50 80 –15 0 +4 –4 +6,5 –6,5 +9,5 –9,5 +15 –15 +10 +2

–19 +4 –21,5 +6,5 –24,5 +9,5 –30 +15 –25 –2
–15,5 +1,5 –18 +3 –20 +5 –25 +10 –22 –5

80 120 –20 0 +5 –5 +7,5 –7,5 +11 –11 +17,5 –17,5 +13 +3

–25 +5 –27,5 +7,5 –31 +11 –37,5 +17,5 –33 –3
–22 +2 –23 +3 –25 +5 –31 +11 –30 –6

120 180 –25 0 +6 –6 +9 –9 +12,5 –12,5 +20 –20 +15 +3

–31 +6 –34 +9 –37,5 +12,5 –45 +20 –40 –3
–27 +2 –28 +3 –31 +6 –37 +12 –36 –7

180 250 –30 0 +7 –7 +10 –10 +14,5 –14,5 +23 –23 +18 +4
–37 +7 –40 +10 –44,5 +14,5 –53 +23 –48 –4
–32 +2 –34 +4 –36 +6 –43 +13 –43 –9

250 315 –35 0 +8 –8 +11,5 –11,5 +16 –16 +26 –26 +20 +4
–4 +8 –46,5 +11,5 –51 +16 –61 +26 –55 –4
–37 +2 –39 +4 –42 +7 –49 +14 –49 –10

315 400 –40 0 +9 –9 +12,5 –12,5 +18 –18 +28,5 –28,5 +22 +4
–49 +9 –52,5 +12,5 –58 +18 –68,5 +28,5 –62 –4
–42 +2 –44 +4 –47 +7 –55 +15 –55 –11

400 500 –45 0 +10 –10 +13,5 –13,5 +20 –20 +31,5 –31,5 +25 +5
–55 +10 –58,5 +13,5 –65 +20 –76,5 +31,5 –70 –5
–48 +3 –49 +4 –53 +8 –62 +17 –63 –12

500 630 –50 0 – – +14 –14 +22 –22 +35 –35 – –

– – –64 +14 –72 +22 –85 +35 – –
– – –54 +4 –59 +9 –69 +19 – –

158
 Tolerances and resultant its

Table 13

Shaft tolerances and resultant its

+
0
–

Shaft Bearing Shaft diameter deviations, resultant its1)

Nominal diameter Bore diameter Tolerance classes
tolerance
d tΔdmp js4� js5� js6� js7� k4�

Deviations (shaft diameter)

Theoretical interference (–)/clearance (+)
over incl low high Probable interference (–)/clearance (+)

mm µm µm

630 800 –75 0 – – +16 –16 +25 –25 +40 –40 – –

– – –91 +16 –100 +25 –115 +40 – –
– – –79 +4 –83 +8 –93 +18 – –

800 1 000 –100 0 – – +18 –18 +28 –28 +45 –45 – –

– – –118 +18 –128 +28 –145 +45 – –
– – –104 +4 –108 +8 –118 +18 – –

1 000 1 250 –125 0 – – +21 –21 +33 –33 +52 –52 – –

– – –146 +21 –158 +33 –177 +52 – –
– – –129 +4 –134 +9 –145 +20 – –

1 250 1 600 –160 0 – – +25 –25 +39 –39 +62 –62 – –

– – –185 +25 –199 +39 –222 +62 – –
– – –164 +4 –169 +9 –182 +22 – –

1 600 2 000 –200 0 – – +30 –30 +46 –46 +75 –75 – –

– – –230 +30 –246 +46 –275 +75 – –

B.6 Bearing interfaces

– – –205 +5 –211 +11 –225 +25 – –

1) Values are valid for most bearings with Normal tolerances For exceptions, refer to Tolerances and resultant fits, page 153

159
 B.6 Bearing interfaces

Table 14

Shaft tolerances and resultant its

+
0
–

Shaft Bearing Shaft diameter deviations, resultant its1)

Nominal diameter Bore diameter Tolerance classes
tolerance
d tΔdmp k5� k6� m5� m6� n5�

Deviations (shaft diameter)

Theoretical interference (–)
> ≤ L U Probable interference (–)

mm µm µm

– 3 –8 0 +4 0 +6 0 +6 +2 +8 +2 +8 +4
–12 0 –14 0 –14 –2 –16 –2 –16 –4
–11 –1 –12 –2 –13 –3 –14 –4 –15 –5

3 6 –8 0 +6 +1 +9 +1 +9 +4 +12 +4 +13 +8
–14 –1 –17 –1 –17 –4 –20 –4 –21 –8
–13 –2 –15 –3 –16 –5 –18 –6 –20 –9

6 10 –8 0 +7 +1 +10 +1 +12 +6 +15 +6 +16 +10

–15 –1 –18 –1 –20 –6 –23 –6 –24 –10
–13 –3 –16 –3 –18 –8 –21 –8 –22 –12

10 18 –8 0 +9 +1 +12 +1 15 +7 +18 +7 +20 +12

–17 –1 –20 –1 –23 –7 –26 –7 –28 –12
–15 –3 –18 –3 –21 –9 –24 –9 –26 –14

18 30 –10 0 +11 +2 +15 +2 +17 +8 +21 +8 +24 +15

B.6 Bearing interfaces

–21 –2 –25 –2 –27 –8 –31 –8 –34 –15

–19 –4 –22 –5 –25 –10 –28 –11 –32 –17

30 50 –12 0 +13 +2 +18 +2 +20 +9 +25 +9 +28 +17

–25 –2 –30 –2 –32 –9 –37 –9 –40 –17
–22 –5 –26 –6 –29 –12 –33 –13 –37 –20

50 80 –15 0 +15 +2 +21 +2 +24 +11 +30 +11 +33 +20

–30 –2 –36 –2 –39 –11 –45 –11 –48 –20
–26 –6 –32 –6 –35 –15 –41 –15 –44 –24

80 120 –20 0 +18 +3 +25 +3 +28 +13 +35 +13 +38 +23
–38 –3 –45 –3 –48 –13 –55 –13 –58 –23
–33 –8 –39 –9 –43 –18 –49 –19 –53 –28

120 180 –25 0 +21 +3 +28 +3 +33 +15 +40 +15 +45 +27
–46 –3 –53 –3 –58 –15 –65 –15 –70 –27
–40 –9 –46 –10 –52 –21 –58 –22 –64 –33

180 250 –30 0 +24 +4 +33 +4 +37 +17 +46 +17 +51 +31
–54 –4 –63 –4 –67 –17 –76 –17 –81 –31
–48 –10 –55 –12 –61 –23 –68 –25 –75 –37

250 315 –35 0 +27 +4 +36 +4 +43 +20 +52 +20 +57 +34
–62 –4 –71 –4 –78 –20 –87 –20 –92 –34
–54 –12 –62 –13 –70 –28 –78 –29 –84 –42

315 400 –40 0 +29 +4 +40 +4 +46 +21 +57 +21 +62 +37
–69 –4 –80 –4 –86 –21 –97 –21 –102 –37
–61 –12 –69 –15 –78 –29 –86 –32 –94 –45

400 500 –45 0 +32 +5 +45 +5 +50 +23 +63 +23 +67 +40
–77 –5 –90 –5 –95 –23 –108 –23 –112 –40
–68 –14 –78 –17 –86 –32 –96 –35 –103 –49

160
 Tolerances and resultant its

Table 14

Shaft tolerances and resultant its

+
0
–

Shaft Bearing Shaft diameter deviations, resultant its1)

Nominal diameter Bore diameter Tolerance classes
tolerance
d tΔdmp k5� k6� m5� m6� n5�

Deviations (shaft diameter)

Theoretical interference (–)
> ≤ L U Probable interference (–)

mm µm µm

500 630 –50 0 +29 0 +44 0 +55 +26 +70 +26 +73 +44
–78 0 –94 0 –105 –26 –120 –26 –122 –44
–68 –10 –81 –13 –94 –36 –107 –39 –112 –54
630 800 –75 0 +32 0 +50 0 +62 +30 +80 +30 +82 +50
–107 0 –125 0 –137 –30 –155 –30 –157 –50
–95 –12 –108 –17 –125 –42 –138 –47 –145 –62

800 ✣ ✤✤✤ –100 0 +36 0 +56 0 +70 +34 +90 +34 +92 +56
–136 0 –156 0 –170 –34 –190 –34 –192 –56
–122 –14 –136 –20 –156 –48 –170 –54 –178 –70

✣ ✤✤✤ ✣ ✥✦✤ –125 0 +42 0 +66 0 +82 +40 +106 +40 +108 +66
–167 0 –191 0 –207 –40 –231 –40 –233 –66
–150 –17 –167 –24 –190 –57 –207 –64 –216 –83

✣ ✥✦✤ ✣ ✧✤✤ –160 0 +50 0 +78 0 +98 +48 +126 +48 +128 +78
–210 0 –238 0 –258 –48 –286 –48 –288 –78

B.6 Bearing interfaces

–189 –21 –208 –30 –237 –69 –256 –78 –267 –99

✣ ✧✤✤ ✥ ✤✤✤ –200 0 +60 0 +92 0 +118 +58 +150 +58 +152 +92
–260 0 –292 0 –318 –58 –350 –58 –352 –92
–235 –25 –257 –35 –293 –83 –315 –93 –327 –117

1) Values are valid for most bearings with Normal tolerances For exceptions, refer to Tolerances and resultant fits, page 153

161
 B.6 Bearing interfaces

Table 15

Shaft tolerances and resultant its

+
0
–

Shaft Bearing Shaft diameter deviations, resultant its1)

Nominal diameter Bore diameter Tolerance classes
tolerance
d tΔdmp n6� p6� p7� r6� r7�
Deviations (shaft diameter)
Theoretical interference (–)
over incl low high Probable interference (–)

mm µm µm

50 80 –15 0 +39 +20 +51 +32 +62 +32 – – – –

–54 –20 –66 –32 –77 –32 – – – –
–50 –24 –62 –36 –72 –38 – – – –

80 100 –20 0 +45 +23 +59 +37 +72 +37 +73 +51 +86 +51
–65 –23 –79 –37 –92 –37 –93 –51 –106 –51
–59 –29 –73 –43 –85 –44 –87 –57 –99 –58

100 120 –20 0 +45 +23 +59 +37 +72 +37 +76 +54 +89 +54
–65 –23 –79 –37 –92 –37 –96 –54 –109 –54
–59 –29 –73 –43 –85 –44 –90 –60 –102 –61

120 140 –25 0 +52 +27 +68 +43 +83 +43 +88 +63 +103 +63
–77 –27 –93 –43 –108 –43 –113 –63 –128 –63
–70 –34 –86 –50 –100 –51 –106 –70 –120 –71

140 160 –25 0 +52 +27 +68 +43 +83 +43 +90 +65 +105 +65
–77 –27 –93 –43 –108 –43 –115 –65 –130 –65
–70 –34 –86 –50 –100 –51 –108 –72 –122 –73
B.6 Bearing interfaces

160 180 –25 0 +52 +27 +68 +43 +83 +43 +93 +68 +108 +68
–77 –27 –93 –43 –108 –43 –118 –68 –133 –68
–70 –34 –86 –50 –100 –51 –111 –75 –125 –76

180 200 –30 0 +60 +31 +79 +50 +96 +50 +106 +77 +123 +77
–90 –31 –109 –50 –126 –50 –136 –77 –153 –77
–82 –39 –101 –58 –116 –60 –128 –85 –143 –87

200 225 –30 0 +60 +31 +79 +50 +96 +50 +109 +80 +126 +80
–90 –31 –109 –50 –126 –50 –139 –80 –156 –80
–82 –39 –101 –58 –116 –60 –131 –88 –146 –90

225 250 –30 0 +60 +31 +79 +50 +96 +50 +113 +84 +130 +84
–90 –31 –109 –50 –126 –50 –143 –84 –160 –84
–82 –39 –101 –58 –116 –60 –135 –92 –150 –94

250 280 –35 0 +66 +34 +88 +56 +108 +56 +126 +94 +146 +94
–101 –34 –123 –56 –143 –56 –161 –94 –181 –94
–92 –43 –114 –65 –131 –68 –152 –103 –169 –106

280 315 –35 0 +66 +34 +88 +56 +108 +56 +130 +98 +150 +98
–101 –34 –123 –56 –143 –56 –165 –98 –185 –98
–92 –43 –114 –65 –131 –68 –156 –107 –173 –110

315 355 –40 0 +73 +37 +98 +62 +119 +62 +144 +108 +165 +108
–113 –37 –138 –62 –159 –62 –184 –108 –205 –108
–102 –48 –127 –73 –146 –75 –173 –119 –192 –121

355 400 –40 0 +73 +37 +98 +62 +119 +62 +150 +114 +171 +114
–113 –37 –138 –62 –159 –62 –190 –114 –211 –114
–102 –48 –127 –73 –146 –75 –179 –125 –198 –127

400 450 –45 0 +80 +40 +108 +68 +131 +68 +166 +126 +189 +126
–125 –40 –153 –68 –176 –68 –211 –126 –234 –126
–113 –52 –141 –80 –161 –83 –199 –138 –219 –141

162
 Tolerances and resultant its

Table 15

Shaft tolerances and resultant its

+
0
–

Shaft Bearing Shaft diameter deviations, resultant its1)

Nominal diameter Bore diameter Tolerance classes
tolerance
d tΔdmp n6� p6� p7� r6� r7�
Deviations (shaft diameter)
Theoretical interference (–)
over incl low high Probable interference (–)

mm µm µm

450 500 –45 0 +80 +40 +108 +68 +131 +68 +172 +132 +195 +132
–125 –40 –153 –68 –176 –68 –217 –132 –240 –132
–113 –52 –141 –80 –161 –83 –205 –144 –225 –147

500 560 –50 0 +88 +44 +122 +78 +148 +78 +194 +150 +220 +150
–138 –44 –172 –78 –198 –78 –244 –150 –270 –150
–125 –57 –159 –91 –182 –94 –231 –163 –254 –166

560 630 –50 0 +88 +44 +122 +78 +148 +78 +199 +155 +225 +155
–138 –44 –172 –78 –198 –78 –249 –155 –275 –155
–125 –57 –159 –91 –182 –94 –236 –168 –259 –171

630 710 –75 0 +100 +50 +138 +88 +168 +88 +225 +175 +255 +175
–175 –50 –213 –88 –243 –88 –300 –175 –330 –175
–158 –67 –196 –105 –221 –110 –283 –192 –308 –197

710 800 –75 0 +100 +50 +138 +88 +168 +88 +235 +185 +265 +185
–175 –50 –213 –88 –243 –88 –310 –185 –340 –185
–158 –67 –196 –105 –221 –110 –293 –202 –318 –207

B.6 Bearing interfaces

800 900 –100 0 +112 +56 +156 +100 +190 +100 +266 +210 +300 +210
–212 –56 –256 –100 –290 –100 –366 –210 –400 –210
–192 –76 –236 –120 –263 –127 –346 –230 –373 –237

900 1 000 –100 0 +112 +56 +156 +100 +190 +100 +276 +220 +310 +220
–212 –56 –256 –100 –290 –100 –376 –220 –410 –220
–192 –76 –236 –120 –263 –127 –356 –240 –383 –247

1 000 1 120 –125 0 +132 +66 +186 +120 +225 +120 +316 +250 +355 +250
–257 –66 –311 –120 –350 –120 –441 –250 –480 –250
–233 –90 –287 –144 –317 –153 –417 –274 –447 –283

1 120 1 250 –125 0 +132 +66 +186 +120 +225 +120 +326 +260 +365 +260
–257 –66 –311 –120 –350 –120 –451 –260 –490 –260
–233 –90 –287 –144 –317 –153 –427 –284 –457 –293

1 250 1 400 –160 0 +156 +78 +218 +140 +265 +140 +378 +300 +425 +300
–316 –78 –378 –140 –425 –140 –538 –300 –585 –300
–286 –108 –348 –170 –385 –180 –508 –330 –545 –340

1 400 1 600 –160 0 +156 +78 +218 +140 +265 +140 +408 +330 +455 +330
–316 –78 –378 –140 –425 –140 –568 –330 –615 –330
–286 –108 –348 –170 –385 –180 –538 –360 –575 –370

1 600 1 800 –200 0 +184 +92 +262 +170 +320 +170 +462 +370 +520 +370
–384 –92 –462 –170 –520 –170 –662 –370 –720 –370
–349 –127 –427 –205 –470 –220 –627 –405 –670 –420

1 800 2 000 –200 0 +184 +92 +262 +170 +320 +170 +492 +400 +550 +400
–384 –92 –462 –170 –520 –170 –692 –400 –750 –400
–349 –127 –427 –205 –470 –220 –657 –435 –700 –450

1) Values are valid for most bearings with Normal tolerances For exceptions, refer to Tolerances and resultant fits, page 153

163
 B.6 Bearing interfaces

Table 16

Shaft tolerances and resultant its

Shaft Bearing Shaft diameter deviations, resultant its1)

Nominal diameter Bore diameter Tolerance classes
tolerance
d tΔdmp r6+IT6 r7+IT7
Deviations (shaft diameter)
Theoretical interference (–)
over incl low high Probable interference (–)

mm µm µm

315 355 –40 0 +180 +144 +222 +165

–220 –144 –262 –165
–209 –155 –248 –179

355 400 –40 0 +186 +150 +228 +171

–226 –150 –268 –171
–215 –161 –254 –185

400 450 –45 0 +206 +166 +252 +189

–251 –166 –297 –189
–239 –178 –282 –204

450 500 –45 0 +212 +172 +258 +195

–257 –172 –303 –195
–245 –184 –288 –210

500 560 –50 0 +238 +194 +290 +220

–288 –194 –340 –220
–274 –208 –323 –237
B.6 Bearing interfaces

560 630 –50 0 +243 +199 +295 +225

–293 –199 –345 –225
–279 –213 –328 –242

630 710 –75 0 +275 +225 +335 +255

–350 –225 –410 –255
–333 –242 –387 –278

710 800 –75 0 +285 +235 +345 +265

–360 –235 –420 –265
–343 –252 –397 –288

800 900 –100 0 +322 +266 +390 +300

–422 –266 –490 –300
–401 –287 –462 –328

900 1 000 –100 0 +332 +276 +400 +310

–432 –276 –500 –310
–411 –297 –472 –338

1 000 1 120 –125 0 +382 +316 +460 +355

–507 –316 –585 –355
–482 –341 –552 –388

1 120 1 250 –125 0 +392 +326 +470 +365

–517 –326 –595 –365
–492 –351 –562 –398

164
 Tolerances and resultant its

Table 16

Shaft tolerances and resultant its

Shaft Bearing Shaft diameter deviations, resultant its1)

Nominal diameter Bore diameter Tolerance classes
tolerance
d tΔdmp r6+IT6 r7+IT7
Deviations (shaft diameter)
Theoretical interference (–)
over incl low high Probable interference (–)

mm µm µm

1 250 1 400 –160 0 +456 +378 +550 +425

–616 –378 –710 –425
–586 –408 –669 –466

1 400 1 600 –160 0 +486 +408 +580 +455

–646 –408 –740 –455
–616 –438 –699 –496

1 600 1 800 –200 0 +554 +462 +670 +520

–754 –462 –870 –520
–718 –498 –820 –570

1 800 2 000 –200 0 +584 +492 +700 +550

–784 –492 –900 –550
–748 –528 –850 –600

B.6 Bearing interfaces

1) Values are valid for most bearings with Normal tolerances For exceptions, refer to Tolerances and resultant fits, page 153

165
 B.6 Bearing interfaces

Table 17

Housing tolerances and resultant its

+
0
–

Housing Bearing Housing bore diameter deviations, resultant its1)

Nominal bore Outside diameter Tolerance classes
diameter tolerance
D tΔDmp F7� G6� G7� H5� H6�

Deviations (housing bore diameter)

Theoretical clearance (+)
over incl low high Probable clearance (+)

mm µm µm

6 10 0 –8 +13 +28 +5 +14 +5 +20 0 +6 0 +9

+13 +36 +5 +22 +5 +28 0 +14 0 +17
+16 +33 +7 +20 +8 +25 +2 +12 +2 +15

10 18 0 –8 +16 +34 +6 +17 +6 +24 0 +8 0 +11

+16 +42 +6 +25 +6 +32 0 +16 0 +19
+19 +39 +8 +23 +9 +29 +2 +14 +2 +17

18 30 0 –9 +20 +41 +7 +20 +7 +28 0 +9 +0 +13

+20 +50 +7 +29 +7 +37 0 +18 0 +22
+23 +47 +10 +26 +10 +34 +2 +16 +3 +19

30 50 0 –11 +25 +50 +9 +25 +9 +34 0 +11 0 +16

+25 +61 +9 +36 +9 +45 0 +22 0 +27
+29 +57 +12 +33 +13 +41 +3 +19 +3 +24

50 80 0 –13 +30 +60 +10 +29 +10 +40 0 +13 0 +19

+30 +73 +10 +42 +10 +53 0 +26 0 +32
B.6 Bearing interfaces

+35 +68 +14 +38 +15 +48 +3 +23 +4 +28

80 120 0 –15 +36 +71 +12 +34 +12 +47 0 +15 0 +22
+36 +86 +12 +49 +12 +62 0 +30 0 +37
+41 +81 +17 +44 +17 +57 +4 +26 +5 +32

120 150 0 –18 +43 +83 +14 +39 +14 +54 0 +18 0 +25
+43 +101 +14 +57 +14 +72 0 +36 0 +43
+50 +94 +20 +51 +21 +65 +5 +31 +6 +37

150 180 0 –25 +43 +83 +14 +39 +14 +54 0 +18 0 +25
+43 +108 +14 +64 +14 +79 0 +43 0 +50
+51 +100 +21 +57 +22 +71 +6 +37 +7 +43

180 250 0 –30 +50 +96 +15 +44 +15 +61 0 +20 0 +29
+50 +126 +15 +74 +15 +91 0 +50 0 +59
+60 +116 +23 +66 +25 +81 +6 +44 +8 +51

250 315 0 –35 +56 +108 +17 +49 +17 +69 0 +23 0 +32
+56 +143 +17 +84 +17 +104 0 +58 0 +67
+68 +131 +26 +75 +29 +92 +8 +50 +9 +58

315 400 0 –40 +62 +119 +18 +54 +18 +75 0 +25 0 +36
+62 +159 +18 +94 +18 +115 0 +65 0 +76
+75 +146 +29 +83 +31 +102 +8 +57 +11 +65

400 500 0 –45 +68 +131 +20 +60 +20 +83 0 +27 0 +40
+68 +176 +20 +105 +20 +128 0 +72 0 +85
+83 +161 +32 +93 +35 +113 +9 +63 +12 +73

500 630 0 –50 +76 +146 +22 +66 +22 +92 0 +28 0 +44
+76 +196 +22 +116 +22 +142 0 +78 0 +94
+92 +180 +35 +103 +38 +126 +10 +68 +13 +81

630 800 0 –75 +80 +160 +24 +74 +24 +104 0 +32 0 +50
+80 +235 +24 +149 +24 +179 0 +107 0 +125
+102 +213 +41 +132 +46 +157 +12 +95 +17 +108

166
 Tolerances and resultant its

Table 17

Housing tolerances and resultant its

+
0
–

Housing Bearing Housing bore diameter deviations, resultant its1)

Nominal bore Outside diameter Tolerance classes
diameter tolerance
D tΔDmp F7� G6� G7� H5� H6�

Deviations (housing bore diameter)

Theoretical clearance (+)
over incl low high Probable clearance (+)

mm µm µm

800 1 000 0 –100 +86 +176 +26 +82 +26 +116 0 +36 0 +56
+86 +276 +26 +182 +26 +216 0 +136 0 +156
+113 +249 +46 +162 +53 +189 +14 +122 +20 +136

1 000 1 250 0 –125 +98 +203 +28 +94 +28 +133 0 +42 0 +66
+98 +328 +28 +219 +28 +258 0 +167 0 +191
+131 +295 +52 +195 +61 +225 +17 +150 +24 +167

1 250 1 600 0 –160 +110 +235 +30 +108 +30 +155 0 +50 0 +78
+110 +395 +30 +268 +30 +315 0 +210 0 +238
+150 +355 +60 +238 +70 +275 +21 +189 +30 +208

1 600 2 000 0 –200 +120 +270 +32 +124 +32 +182 0 +60 0 +92
+120 +470 +32 +324 +32 +382 0 +260 0 +292
+170 +420 +67 +289 +82 +332 +25 +235 +35 +257

2 000 2 500 0 –250 +130 +305 +34 +144 +34 +209 0 +70 0 +110
+130 +555 +34 +394 +34 +459 0 +320 0 +360

B.6 Bearing interfaces

+189 +496 +77 +351 +93 +400 +30 +290 +43 +317

1) Values are valid for most bearings with Normal tolerances For exceptions, refer to Tolerances and resultant fits, page 153

167
 B.6 Bearing interfaces

Table 18

Housing tolerances and resultant its

+
0
–
Housing Bearing Housing bore diameter deviations, resultant its1)
Nominal bore Outside diameter Tolerance classes
diameter tolerance
D tΔDmp H7� H8� H9� H10� J6�

Deviations (housing bore diameter)

Theoretical interference (–)/clearance (+)
over incl low high Probable interference (–)/clearance (+)

mm µm µm

6 10 0 –8 0 +15 0 +22 0 +36 0 +58 –4 +5

0 +23 0 +30 0 +44 0 +66 –4 +13
+3 +20 +3 +27 +3 +41 +3 +63 –2 +11

10 18 0 –8 0 +18 0 +27 0 +43 0 +70 –5 +6

0 +26 0 +35 0 +51 0 +78 –5 +14
+3 +23 +3 +32 +3 +48 +3 +75 –3 +12

18 30 0 –9 0 +21 0 +33 0 +52 0 +84 –5 +8

0 +30 0 +42 0 +61 0 +93 –5 +17
+3 +27 +3 +39 +4 +57 +4 +89 –2 +14

30 50 0 –11 0 +25 0 +39 0 +62 0 +100 –6 +10

0 +36 0 +50 0 +73 0 +111 –6 +21
+4 +32 +4 +46 +5 +68 +5 +106 –3 +18

50 80 0 –13 0 +30 0 +46 0 +74 0 +120 –6 +13

0 +43 0 +59 0 +87 0 +133 –6 +26
B.6 Bearing interfaces

+5 +38 +5 +54 +5 +82 +6 +127 –2 +22

80 120 0 –15 0 +35 0 +54 0 +87 0 +140 –6 +16

0 +50 0 +69 0 +102 0 +155 –6 +31
+5 +45 +6 +63 +6 +96 +7 +148 –1 +26

120 150 0 –18 0 +40 0 +63 0 +100 0 +160 –7 +18

0 +58 0 +81 0 +118 0 +178 –7 +36
+7 +51 +7 +74 +8 +110 +8 +170 –1 +30

150 180 0 –25 0 +40 0 +63 0 +100 0 +160 –7 +18

0 +65 0 +88 0 +125 0 +185 –7 +43
+8 +57 +10 +78 +10 +115 +11 +174 0 +36

180 250 0 –30 0 +46 0 +72 0 +115 0 +185 –7 +22

0 +76 0 +102 0 +145 0 +215 –7 +52
+10 +66 +12 +90 +13 +132 +13 +202 +1 +44

250 315 0 –35 0 +52 0 +81 0 +130 0 +210 –7 +25

0 +87 0 +116 0 +165 0 +245 –7 +60
+12 +75 +13 +103 +15 +150 +16 +229 +2 +51

315 400 0 –40 0 +57 0 +89 0 +140 0 +230 –7 +29

0 +97 0 +129 0 +180 0 +270 –7 +69
+13 +84 +15 +114 +17 +163 +18 +252 +4 +58

400 500 0 –45 0 +63 0 +97 0 +155 0 +250 –7 +33

0 +108 0 +142 0 +200 0 +295 –7 +78
+15 +93 +17 +125 +19 +181 +20 +275 +5 +66

500 630 0 –50 0 +70 0 +110 0 +175 0 +280 – –

0 +120 0 +160 0 +225 0 +330 – –
+16 +104 +19 +141 +21 +204 +22 +308 – –

168
 B.6 Bearing interfaces

Table 18

Housing tolerances and resultant its

+
0
–
Housing Bearing Housing bore diameter deviations, resultant its1)
Nominal bore Outside diameter Tolerance classes
diameter tolerance
D tΔDmp H7� H8� H9� H10� J6�

Deviations (housing bore diameter)

Theoretical interference (–)/clearance (+)
over incl low high Probable interference (–)/clearance (+)

mm µm µm

6 10 0 –8 0 +15 0 +22 0 +36 0 +58 –4 +5

0 +23 0 +30 0 +44 0 +66 –4 +13
+3 +20 +3 +27 +3 +41 +3 +63 –2 +11

10 18 0 –8 0 +18 0 +27 0 +43 0 +70 –5 +6

0 +26 0 +35 0 +51 0 +78 –5 +14
+3 +23 +3 +32 +3 +48 +3 +75 –3 +12

18 30 0 –9 0 +21 0 +33 0 +52 0 +84 –5 +8

0 +30 0 +42 0 +61 0 +93 –5 +17
+3 +27 +3 +39 +4 +57 +4 +89 –2 +14

30 50 0 –11 0 +25 0 +39 0 +62 0 +100 –6 +10

0 +36 0 +50 0 +73 0 +111 –6 +21
+4 +32 +4 +46 +5 +68 +5 +106 –3 +18

50 80 0 –13 0 +30 0 +46 0 +74 0 +120 –6 +13

0 +43 0 +59 0 +87 0 +133 –6 +26
B.6 Bearing interfaces

+5 +38 +5 +54 +5 +82 +6 +127 –2 +22

80 120 0 –15 0 +35 0 +54 0 +87 0 +140 –6 +16

0 +50 0 +69 0 +102 0 +155 –6 +31
+5 +45 +6 +63 +6 +96 +7 +148 –1 +26

120 150 0 –18 0 +40 0 +63 0 +100 0 +160 –7 +18

0 +58 0 +81 0 +118 0 +178 –7 +36
+7 +51 +7 +74 +8 +110 +8 +170 –1 +30

150 180 0 –25 0 +40 0 +63 0 +100 0 +160 –7 +18

0 +65 0 +88 0 +125 0 +185 –7 +43
+8 +57 +10 +78 +10 +115 +11 +174 0 +36

180 250 0 –30 0 +46 0 +72 0 +115 0 +185 –7 +22

0 +76 0 +102 0 +145 0 +215 –7 +52
+10 +66 +12 +90 +13 +132 +13 +202 +1 +44

250 315 0 –35 0 +52 0 +81 0 +130 0 +210 –7 +25

0 +87 0 +116 0 +165 0 +245 –7 +60
+12 +75 +13 +103 +15 +150 +16 +229 +2 +51

315 400 0 –40 0 +57 0 +89 0 +140 0 +230 –7 +29

0 +97 0 +129 0 +180 0 +270 –7 +69
+13 +84 +15 +114 +17 +163 +18 +252 +4 +58

400 500 0 –45 0 +63 0 +97 0 +155 0 +250 –7 +33

0 +108 0 +142 0 +200 0 +295 –7 +78
+15 +93 +17 +125 +19 +181 +20 +275 +5 +66

500 630 0 –50 0 +70 0 +110 0 +175 0 +280 – –

0 +120 0 +160 0 +225 0 +330 – –
+16 +104 +19 +141 +21 +204 +22 +308 – –

168
 Tolerances and resultant its

Table 18

Housing tolerances and resultant its

+
0
–
Housing Bearing Housing bore diameter deviations, resultant its1)
Nominal bore Outside diameter Tolerance classes
diameter tolerance
D tΔDmp H7� H8� H9� H10� J6�

Deviations (housing bore diameter)

Theoretical interference (–)/clearance (+)
over incl low high Probable interference (–)/clearance (+)

mm µm µm

630 800 0 –75 0 +80 0 +125 0 +200 0 +320 – –

0 +155 0 +200 0 +275 0 +395 – –
+22 +133 +27 +173 +30 +245 +33 +362 – –

800 1 000 0 –100 0 +90 0 +140 0 +230 0 +360 – –

0 +190 0 +240 0 +330 0 +460 – –
+27 +163 +33 +207 +39 +291 +43 +417 – –

1 000 1 250 0 –125 0 +105 0 +165 0 +260 0 +420 – –

0 +230 0 +290 0 +385 0 +545 – –
+33 +197 +41 +249 +48 +337 +53 +492 – –

1 250 1 600 0 –160 0 +125 0 +195 0 +310 0 +500 – –

0 +285 0 +355 0 +470 0 +660 – –
+40 +245 +51 +304 +60 +410 +67 +593 – –

1 600 2 000 0 –200 0 +150 0 +230 0 +370 0 +600 – –

0 +350 0 +430 0 +570 0 +800 – –

B.6 Bearing interfaces

+50 +300 +62 +368 +74 +496 +83 +717 – –

2 000 2 500 0 –250 0 +175 0 +280 0 +440 0 +700 – –

0 +425 0 +530 0 +690 0 +950 – –
+59 +366 +77 +453 +91 +599 +103 +847 – –

1) Values are valid for most bearings with Normal tolerances For exceptions, refer to Tolerances and resultant fits, page 153

169
 B.6 Bearing interfaces

Table 19

Housing tolerances and resultant its

+
0
–

Housing Bearing Housing bore diameter deviations, resultant its1)

Nominal bore Outside diameter Tolerance classes
diameter tolerance
D tΔDmp J7� JS5� JS6� JS7� K5�

Deviations (housing bore diameter)

Theoretical interference (–)/clearance (+)
over incl low high Probable interference (–)/clearance (+)

mm µm µm

6 10 0 –8 –7 +8 –3 +3 –4,5 +4,5 –7,5 +7,5 –5 +1

–7 +16 –3 +11 –4,5 +12,5 –7,5 +15,5 –5 +9
–4 +13 –1 +9 –3 +11 –5 +13 –3 +7

10 18 0 –8 –8 +10 –4 +4 –5,5 +5,5 –9 +9 –6 +2

–8 +18 –4 +12 –5,5 +13,5 –9 +17 –6 +10
–5 +15 –2 +10 –3 +11 –6 +14 –4 +8

18 30 0 –9 –9 +12 –4,5 +4,5 –6,5 +6,5 –10,5 +10,5 –8 +1

–9 +21 –4,5 +13,5 –6,5 +15,5 –10,5 +19,5 –8 +10
–6 +18 –2 +11 –4 +13 –7 +16 –6 +8

30 50 0 –11 –11 +14 –5,5 +5,5 –8 +8 –12,5 +12,5 –9 +2

–11 +25 –5,5 +16,5 –8 +19 –12,5 +23,5 –9 +13
–7 +21 –3 +14 –5 +16 –9 +20 –6 +10

50 80 0 –13 –12 +18 –6,5 +6,5 –9,5 +9,5 –15 +15 –10 +3
B.6 Bearing interfaces

–12 +31 –6,5 +19,5 –9,5 +22,5 –15 +28 –10 +16
–7 +26 –3 +16 –6 +19 –10 +23 –7 +13

80 120 0 –15 –13 +22 –7,5 +7,5 –11 +11 –17,5 +17,5 –13 +2
–13 +37 –7,5 +22,5 –11 +26 –17,5 +32,5 –13 +17
–8 +32 –4 +19 –6 +21 –12 +27 –9 +13

120 150 0 –18 –14 +26 –9 +9 –12,5 +12,5 –20 +20 –15 +3
–14 +44 –9 +27 –12,5 +30,5 –20 +38 –15 +21
–7 +37 –4 +22 –7 +25 –13 +31 –10 +16

150 180 0 –25 –14 +26 –9 +9 –12,5 +12,5 –20 +20 –15 +3
–14 +51 –9 +34 –12,5 +37,5 –20 +45 –15 +28
–6 +43 –3 +28 –6 +31 –12 +37 –9 +22

180 250 0 –30 –16 +30 –10 +10 –14,5 +14,5 –23 +23 –18 +2
–16 +60 –10 +40 –14,5 +44,5 –23 +53 –18 +32
–6 +50 –4 +34 –6 +36 –13 +43 –12 +26

250 315 0 –35 –16 +36 –11,5 +11,5 –16 +16 –26 +26 –20 +3
–16 +71 –11,5 +46,5 –16 –51 –26 +61 –20 +38
–4 +59 –4 +39 –7 +42 –14 +49 –12 +30

315 400 0 –40 –18 +39 –12,5 +12,5 –18 +18 –28,5 +28,5 –22 +3
–18 +79 –12,5 +52,5 –18 +58 –28,5 +68,5 –22 +43
–5 +66 –4 +44 –7 +47 –15 +55 –14 +35

400 500 0 –45 –20 +43 –13,5 +13,5 –20 +20 –31,5 +31,5 –25 +2
–20 +88 –13,5 +58,5 –20 +65 –31,5 +76,5 –25 +47
–5 +73 –4 +49 –8 +53 –17 +62 –16 +38

500 630 0 –50 – – –14 +14 –22 +22 –35 +35 – –

– – –14 +64 –22 +72 –35 +85 – –
– – –4 +54 –9 +59 –19 +69 – –

170
 Tolerances and resultant its

Table 19

Housing tolerances and resultant its

+
0
–

Housing Bearing Housing bore diameter deviations, resultant its1)

Nominal bore Outside diameter Tolerance classes
diameter tolerance
D tΔDmp J7� JS5� JS6� JS7� K5�

Deviations (housing bore diameter)

Theoretical interference (–)/clearance (+)
over incl low high Probable interference (–)/clearance (+)

mm µm µm

630 800 0 –75 – – –16 +16 –25 +25 –40 +40 – –

– – –16 +91 –25 +100 –40 +115 – –
– – –4 +79 –8 +83 –18 +93 – –

800 1 000 0 –100 – – –18 +18 –28 +28 –45 +45 – –

– – –18 +118 –28 +128 –45 +145 – –
– – –4 +104 –8 +108 –18 +118 – –

1 000 1 250 0 –125 – – –21 +21 –33 +33 –52 +52 – –

– – –21 +146 –33 +158 –52 +177 – –
– – –4 +129 –9 +134 –20 +145 – –

1 250 1 600 0 –160 – – –25 +25 –39 +39 –62 +62 – –

– – –25 +185 –39 +199 –62 +222 – –
– – –4 +164 –9 +169 –22 +182 – –

1 600 2 000 0 –200 – – –30 +30 –46 +46 –75 +75 – –

– – –30 +230 –46 +246 –75 +275 – –

B.6 Bearing interfaces

– – –5 +205 –11 +211 –25 +225 – –

2 000 2 500 0 –250 – – –35 +35 –55 +55 –87 +87 – –

– – –35 +285 –55 +305 –87 +337 – –
– – –5 +255 –12 +262 –28 +278 – –

1) Values are valid for most bearings with Normal tolerances For exceptions, refer to Tolerances and resultant fits, page 153

171
 B.6 Bearing interfaces

Table 20

Housing tolerances and resultant its

+
0
–

Housing Bearing Housing bore diameter deviations, resultant its1)

Nominal bore Outside diameter Tolerance classes
diameter tolerance
D tΔDmp K6� K7� M5� M6� M7�

Deviations (housing bore diameter)

Theoretical interference (–)/clearance (+)
over incl low high Probable interference (–)/clearance (+)

mm µm µm

6 10 0 –8 –7 +2 –10 +5 –10 –4 –12 –3 –15 0

–7 +10 –10 +13 –10 +4 –12 +5 –15 +8
–5 +8 –7 +10 –8 +2 –10 +3 –12 +5

10 18 0 –8 –9 +2 –12 +6 –12 –4 –15 –4 –18 0

–9 +10 –12 +14 –12 +4 –15 +4 –18 +8
–7 +8 –9 +11 –10 +2 –13 +2 –15 +5

18 30 0 –9 –11 +2 –15 +6 –14 –4 –17 –4 –21 0

–11 +11 –15 +15 –14 +4 –17 +5 –21 +9
–8 +8 –12 +12 –12 +2 –14 +2 –18 +6

30 50 0 –11 –13 +3 –18 +7 –16 –5 –20 –4 –25 0

–13 +14 –18 +18 –16 +6 –20 +7 –25 +11
–10 +11 –14 +14 –13 +3 –17 +4 –21 +7

50 80 0 –13 –15 +4 –21 +9 –19 –6 –24 –5 –30 0

–15 +17 –21 +22 –19 +7 –24 +8 –30 +13
B.6 Bearing interfaces

–11 +13 –16 +17 –16 +4 –20 +4 –25 +8

80 120 0 –15 –18 +4 –25 +10 –23 –8 –28 –6 –35 0

–18 +19 –25 +25 –23 +7 –28 +9 –35 +15
–13 +14 –20 +20 –19 +3 –23 +4 –30 +10

120 150 0 –18 –21 +4 –28 +12 –27 –9 –33 –8 –40 0

–21 +22 –28 +30 –27 +9 –33 +10 –40 +18
–15 +16 –21 +23 –22 +4 –27 +4 –33 +11

150 180 0 –25 –21 +4 –28 +12 –27 –9 –33 –8 –40 0

–21 +29 –28 +37 –27 +16 –33 +17 –40 +25
–14 +22 –20 +29 –21 +10 –26 +10 –32 +17

180 250 0 –30 –24 +5 –33 +13 –31 –11 –37 –8 –46 0
–24 +35 –33 +43 –31 +19 –37 +22 –46 +30
–16 +27 –23 +33 –25 +13 –29 +14 –36 +20

250 315 0 –35 –27 +5 –36 +16 –36 –13 –41 –9 –52 0
–27 +40 –36 +51 –36 +22 –41 +26 –52 +35
–18 +31 –24 +39 –28 +14 –32 +17 –40 +23

315 400 0 –40 –29 +7 –40 +17 –39 –14 –46 –10 –57 0
–29 +47 –40 +57 –39 +26 –46 +30 –57 +40
–18 +36 –27 +44 –31 +18 –35 +19 –44 +27

400 500 0 –45 –32 +8 –45 +18 –43 –16 –50 –10 –63 0
–32 +53 –45 +63 –43 +29 –50 +35 –63 +45
–20 +41 –30 +48 –34 +20 –38 +23 –48 +30

500 630 0 –50 –44 0 –70 0 – – –70 –26 –96 –26

–44 +50 –70 +50 – – –70 +24 –96 +24
–31 +37 –54 +34 – – –57 +11 –80 +8

172
 Tolerances and resultant its

Table 20

Housing tolerances and resultant its

+
0
–

Housing Bearing Housing bore diameter deviations, resultant its1)

Nominal bore Outside diameter Tolerance classes
diameter tolerance
D tΔDmp K6� K7� M5� M6� M7�

Deviations (housing bore diameter)

Theoretical interference (–)/clearance (+)
over incl low high Probable interference (–)/clearance (+)

mm µm µm

630 800 0 –75 –50 0 –80 0 – – –80 –30 –110 –30

–50 +75 –80 +75 – – –80 +45 –110 +45
–33 +58 –58 +53 – – –63 +28 –88 +23

800 1 000 0 –100 –56 0 –90 0 – – –90 –34 –124 –34

–56 +100 –90 +100 – – –90 +66 –124 +66
–36 +80 –63 +73 – – –70 +46 –97 +39

1 000 1 250 0 –125 –66 0 –105 0 – – –106 –40 –145 –40

–66 +125 –105 +125 – – –106 +85 –145 +85
–42 +101 –72 +92 – – –82 +61 –112 +52

1 250 1 600 0 –160 –78 0 –125 0 – – –126 –48 –173 –48

–78 +160 –125 +160 – – –126 +112 –173 +112
–48 +130 –85 +120 – – –96 +82 –133 +72

1 600 2 000 0 –200 –92 0 –150 0 – – –158 –58 –208 –58

–92 +200 –150 +200 – – –150 +142 –208 +142

B.6 Bearing interfaces

–57 +165 –100 +150 – – –115 +107 –158 +92

2 000 2 500 0 –250 –110 0 –175 0 – – –178 –68 –243 –68

–110 +250 –175 +250 – – –178 +182 –243 +182
–67 +207 –116 +191 – – –135 +139 –184 +123

1) Values are valid for most bearings with Normal tolerances For exceptions, refer to Tolerances and resultant fits, page 153

173
 B.6 Bearing interfaces

Table 21

Housing tolerances and resultant its

+
0
–

Housing Bearing Housing bore diameter deviations, resultant its1)

Nominal bore Outside diameter Tolerance classes
diameter tolerance
D tΔDmp N6� N7� P6� P7�

Deviations (housing bore diameter)

Theoretical interference (–)/clearance (+)
ove incl low high Probable interference (–)/clearance (+)

mm µm µm

6 10 0 –8 –16 –7 –19 –4 –21 –12 –24 –9

–16 +1 –19 +4 –21 –4 –24 –1
–14 –1 –16 +1 –19 –6 –21 –4

10 18 0 –8 –20 –9 –23 –5 –26 –15 –29 –11

–20 –1 –23 +3 –26 –7 –29 –3
–18 –3 –20 0 –24 –9 –26 –6

18 30 0 –9 –24 –11 –28 –7 –31 –18 –35 –14

–24 –2 –28 +2 –31 –9 –35 –5
–21 –5 –25 –1 –28 –12 –32 –8

30 50 0 –11 –28 –12 –33 –8 –37 –21 –42 –17

–28 –1 –33 +3 –37 –10 –42 –6
–25 –4 –29 –1 –34 –13 –38 –10

50 80 0 –13 –33 –14 –39 –9 –45 –26 –51 –21

–33 –1 –39 +4 –45 –13 –51 –8
B.6 Bearing interfaces

–29 –5 –34 –1 –41 –17 –46 –13

80 120 0 –15 –38 –16 –45 –10 –52 –30 –59 –24
–38 –1 –45 +5 –52 –15 –59 –9
–33 –6 –40 0 –47 –20 –54 –14

120 150 0 –18 –45 –20 –52 –12 –61 –36 –68 –28
–45 –2 –52 +6 –61 –18 –68 –10
–39 –8 –45 –1 –55 –24 –61 –17

150 180 0 –25 –45 –20 –52 –12 –61 –36 –68 –28
–45 +5 –52 +13 –61 –11 –68 –3
–38 –2 –44 +5 –54 –18 –60 –11

180 250 0 –30 –51 –22 –60 –14 –70 –41 –79 –33
–51 +8 –60 +16 –70 –11 –79 –3
–43 0 –50 +6 –62 –19 –69 –13

250 315 0 –35 –57 –25 –66 –14 –79 –47 –88 –36
–57 +10 –66 +21 –79 –12 –88 –1
–48 +1 –54 +9 –70 –21 –76 –13

315 400 0 –40 –62 –26 –73 –16 –87 –51 –98 –41
–62 +14 –73 +24 –87 –11 –98 –1
–51 +3 –60 +11 –76 –22 –85 –14

400 500 0 –45 –67 –27 –80 –17 –95 –55 –108 –45
–67 +18 –80 +28 –95 –10 –108 0
–55 +6 –65 +13 –83 –22 –93 –15

500 630 0 –50 –88 –44 –114 –44 –122 –78 –148 –78
–88 +6 –114 +6 –122 –28 –148 –28
–75 –7 –98 –10 –109 –41 –132 –44

174
 Tolerances and resultant its

Table 21

Housing tolerances and resultant its

+
0
–

Housing Bearing Housing bore diameter deviations, resultant its1)

Nominal bore Outside diameter Tolerance classes
diameter tolerance
D tΔDmp N6� N7� P6� P7�

Deviations (housing bore diameter)

Theoretical interference (–)/clearance (+)
over incl low high Probable interference (–)/clearance (+)

mm µm µm

630 800 0 –75 –100 –50 –130 –50 –138 –88 –168 –88
–100 +25 –130 +25 –138 –13 –168 –13
–83 +8 –108 +3 –121 –30 –146 –35

800 1 000 0 –100 –112 –56 –146 –56 –156 –100 –190 –100
–112 +44 –146 +44 –156 0 –190 0
–92 +24 –119 +17 –136 –20 –163 –27

1 000 1 250 0 –125 –132 –66 –171 –66 –186 –120 –225 –120
–132 +59 –171 +59 –186 +5 –225 +5
–108 +35 –138 +26 –162 –19 –192 –28

1 250 1 600 0 –160 –156 –78 –203 –78 –218 –140 –265 –140
–156 +82 –203 +82 –218 +20 –265 +20
–126 +52 –163 +42 –188 –10 –225 –20

1 600 2 000 0 –200 –184 –92 –242 –92 –262 –170 –320 –170
–184 +108 –242 +108 –262 +30 –320 +30

B.6 Bearing interfaces

–149 +73 –192 +58 –227 –5 –270 –20

2 000 2 500 0 –250 –220 –110 –285 –110 –305 –195 –370 –195
–220 +140 –285 +140 –305 +55 –370 +55
–177 +97 –226 +81 –262 +12 –311 –4

1) Values are valid for most bearings with Normal tolerances For exceptions, refer to Tolerances and resultant fits, page 153

175
 B.6 Bearing interfaces

Provisions for Fig. 8

Slots or recesses in the shaft to apply

mounting and withdrawal tools

dismounting
Particularly when large bearings are
involved, SKF recommends that during the
design stage you make provisions to facili-
tate mounting and dismounting, including:

• slots or recesses machined in the shaft or

housing shoulders so that withdrawal
tools can be used (ig. 8)
• threaded holes in the housing shoulders Fig. 9
so that bolts can be used for dismounting Threaded holes in the housing to push
(ig. 9) bearing with bolts from its seat
• oil supply ducts and distribution grooves in
the shaft to enable the oil injection method
to be used (ig. 10)
Recommended dimensions for oil sup-
ply ducts and distribution grooves are
listed in table 22, and for threaded holes
in table 23 When using the oil injection
method, Ra should not exceed 1,6 μm
B.6 Bearing interfaces

Fig. 10

Duct and groove for oil injection

176
 Provisions for mounting and dismounting

Table 22

Recommended dimensions for oil supply ducts and distribution grooves

L
L
3
ba
ra
ha

Seat diameter Dimensions

> ≤ ba ha ra N

mm mm

– 100 3 0,5 2,5 2,5

100 150 4 0,8 3 3
150 200 4 0,8 3 3

200 250 5 1 4 4
250 300 5 1 4 4
300 400 6 1,25 4,5 5

400 500 7 1,5 5 5

500 650 8 1,5 6 6
650 800 10 2 7 7

800 1 000 12 2,5 8 8

L = width of bearing seat

B.6 Bearing interfaces

Table 23

Design and recommended dimensions for threaded holes for connecting oil supply

60°

Na Ga Na Ga

Gc
Gb Gc
Gb
Design A Design B

Thread Design Dimensions

Ga Gb Gc1) Na
max.

– – mm

M6 A 10 8 3
G 1/8 A 12 10 3
G 1/4 A 15 12 5

G 3/8 B 15 12 8
G 1/2 B 18 14 8
G 3/4 B 20 16 8

1) Effective threaded length

177
 B.6 Bearing interfaces

Axial location of Bearings with a Abutments and fillets

bearing rings tapered bore When designing abutments, allow enough
space to avoid contact between rotating and
Depending on conditions and requirements, stationary parts
Typically, it is not suficient to use an inter- common ways of axially locating the inner Shaft and housing illet dimensions should
ference it alone to axially locate a bearing ring of a bearing with a tapered bore are: always be smaller than the bearing chamfer
ring on a cylindrical seat Common ways of radii Heavily loaded shafts can require large
locating bearing rings axially include: • a lock nut for bearings mounted on a illets and a spacing collar may be necessary
tapered seat (ig. 17) (ig. 21)
• shaft or housing shoulders • an adapter sleeve only (ig. 18), if no pre- Appropriate abutment and illet dimen-
• lock nuts or threaded rings (ig. 11 and cise axial positioning is required and the sions are listed in the product tables
ig. 12) axial loads do not exceed the friction
• end plates or housing covers (ig. 13 and between sleeve and shaft
ig. 14) • an adapter sleeve and a distance ring
• distance rings, which support against (ig. 19), if precise axial positioning is
adjacent parts (ig. 15) required or elevated axial loads occur
• snap rings (ig. 16) • a withdrawal sleeve with a distance ring
(or shaft shoulder) and lock nut (ig. 20)
Any axial location should be able to accom-
modate the axial loads that may be applied
to the bearing
B.6 Bearing interfaces

Fig. 11 Fig. 13 Fig. 15

Inner ring supported by a lock nut and Inner ring supported by an end plate and Inner ring supported by a distance ring
shaft shoulder shaft shoulder and lock nut

Fig. 12 Fig. 14 Fig. 16

Outer ring supported by a threaded ring Outer ring supported by housing cover Bearing supported axially by snap rings
and housing shoulder and shaft shoulder

178
 Provisions for mounting and dismounting

Radially free Raceways on

mounted bearings shafts and in
for axial load housings
You may want to use individual bearings in a In order to save space, the rolling elements
bearing arrangement to separately accom- of cylindrical, needle or tapered roller bear-
modate the radial and axial component of ings can run directly on raceways on the
the load A typical arrangement is to use a shaft and/or in the housing To fully exploit
cylindrical roller bearing and a four-point the load carrying capacity, the raceways
contact ball bearing (ig. 22) should comply with certain requirements,
When using an individual bearing to including:
accommodate the axial load, you should
ensure that this bearing is not subjected to • suitable material properties such as
unintended radial loads by: cleanliness, hardness and heat treatment
• suitable roughness and surface texture
• designing the bore diameter of its housing • adequate tolerances for proile, roundness
to be approximately 1 mm larger than the and total run-out
bearing outer diameter
• not clamping its outer ring in the axial For additional information, contact the SKF
direction to permit its free radial positioning application engineering service

Also consider the use of an anti-rotation pin

The designation sufix N2 indicates that the
bearing has two locating slots in the outer
ring

B.6 Bearing interfaces

Fig. 17 Fig. 19 Fig. 21

Bearing on a tapered seat, supported by a Bearing on an adapter sleeve, positioned Spacing collar designed not to contact the
lock nut by a distance ring shaft illet

Fig. 18 Fig. 20 Fig. 22

Bearing on an adapter sleeve Bearing on a withdrawal sleeve Cylindrical roller bearing for radial load
and four-point contact ball bearing for
axial load

179