INTERNATIONAL IS0

STANDARD 8434-4
First edition
1995-04-01

Metallic tube connections for fluid power

and general use -
Part 4:
24” cone connectors with O-ring weld-on
nipples

Raccords de tubes mhalliques pour transmissions hydrauliques et

pneumatiques et applications g&&a/es -
Pat-tie 4: Raccords B cbne B 24”, i embout zi souder B joint torique

Reference number
IS0 8434-4:1995(E)
IS0 8434-4:1995(E)

Contents
Page

1 Scope .............................................................................................. 1

2 Normative references ..................................................................... 1

3 Definitions ....................................................................................... 2

4 Requirements for materials ....................................................... 2

5 Pressure/temperature requirements ......................................... 3

6 Designation of fittings ............................................................... 4

7 Requirements for tubes ............................................................ 7

8 Across-flats dimensions ............................................................ 7

9 Design ....................................................................................... 7

10 Screw threads ......................................................................... 8

11 Manufacture ............................................................................ 8

t2 Assembly instruction ............................................................... 8

13 Procurement information ........................................................ 9

14 Marking of components .......................................................... 9

15 Identification statement (Reference to this part of IS0 8434) 9

Annex

A Port and stud end working pressures and combinations of tube

outside diameters and port and stud end thread sizes ._ . . . 24

Q IS0 1995
All nghts reserved. Unless otherwise specrfred, no part of thus publrcatron may be reproduced
or utrlrzed rn any form or by any means, electronrc or mechanrcal, including photocopying and
mrcrofrlm, without permrssron In wntrng from the publisher
lnternatronal Organlzatron for Standardlzatron
Case Postale 56 l CH-1211 Geneve 20 l Switzerland
Pnnted In Swrtzerland

ii
Q IS0 IS0 8434-4:1995(E)

Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
technical committees. Each member body interested in a subject for
which a technical committee has been established has the right to be
represented on that committee. International organizations, governmental
and non-governmental, in liaison with ISO, also take part in the work. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.

International Standard IS0 8434-4 was prepared by Technical Committee

ISO/TC 131, Fluid power systems, Subcommittee SC 4, Connectors and
similar products and components.
IS0 8434 consists of the following parts, under the general title Metallic
tube connections for fluid power and general use:

- Part 1: 24 degree compression fittings

- Part 2: 37 degree flared fittings

- Part 3: O-ring face seal fittings

- Part 4: 24 degree cone connectors with O-ring weld-on nipples

- Part 5: Test methods for threaded hydraulic fluid power connections

Annex A forms an integral part of this part of IS0 8434.

ill
 Q IS0

Introduction
In fluid power systems, power is transmitted and controlled through a fluid
(liquid or gas) under pressure within an enclosed circuit. In general appli-
cations, a fluid may be conveyed under pressure. Components may be
connected through their ports by connections (fittings) and conductors.
Tubes are rigid conductors; hoses are flexible conductors.

iv
INTERNATIONAL STANDARD 0 IS0 IS0 8434-4: 1995(E)

Metallic tube connections for fluid power and general

use -

Part 4:
24” cone connectors with O-ring weld-on nipples

1 Scope 2 Normative references

The following standards contain provisions which,

through reference in this text, constitute provisions
This part of IS0 8434 specifies general and dimen- of this part of IS0 8434. At the time of publication, the
sional requirements for the design and performance editions indicated were valid. All standards are subject
of 24” cone connectors with O-ring weld-on nipples to revision, and parties to agreements based on this
that are suitable for use with steel and stainless steel part of IS0 8434 are encouraged to investigate the
tubes with outside diameters from 6 mm to 42 mm, possibility of applying the most recent editions of the
inclusive. These fittings are for use in fluid power and standards indicated below. Members of IEC and IS0
general applications where elastomeric seals can be maintain registers of currently valid International
used, within the limits of pressure and temperature Standards.
specified in this part of IS0 8434. S series fittings in
accordance with this part of IS0 8434 may be used IS0 48: 1994, Rubber, vulcanized or thermoplastic -
at working pressures up to 63 MPa (630 bar’)). L- Determination of hardness (hardness between 70
series fittings in accordance with this part of IS0 8434 IRHD and 100 IRHDI.
may be used at working pressures up to 25 MPa
(250 bar) (see table 1). IS0 228-l : 1994, Pipe threads where pressure-tight
joints are not made on the threads - Part 7: Dimen-
They are intended for the connection of tubes and sions, tolerances and designation.
hose fittings to ports in accordance with IS0 6149-1,
IS0 1179-I and IS0 9974-l. IS0 261 :-2), IS0 general-purpose metric screw
threads - General plan.
NOTES
IS0 1127:1992, Stainless steel tubes - Dimensions,
1 For new designs in hydraulic fluid power applications,
see the requirements given in 9.6. tolerances and conventional masses per unit length.

2 For use under conditions outside the pressure and/or IS0 1179-1 :-3), Connections for genera/ use and fluid
temperature limits specified, see 5.4. power - Ports and stud ends with IS0 228-l threads

1) 1 bar = 0.1 MPa = IO5 Pa; 1 MPa = 1 N/mm2

2) To be published. (Revision of IS0 261:1973)
3) To be published.
IS0 8434-4: 1995(E) 0 IS0

with elastomeric or metal-to-metal sealing - Part 7: IS0 9974-l :- 3), Connections for general use and fluid
Threaded ports. power - Ports and stud ends with IS0 267 threads
with elastomeric or metal-to-metal sealing - Part 7:
IS0 11 79-2:-3), Connections for general use and fluid Threaded ports.
power - Ports and stud ends with IS0 228-l threads
with elastomeric or metal-to-metal sealing - Part 2: IS0 9974-2:-3’, Connections for general use and fluid
Heavy-duty (S series) and light-duty (L series) stud power - Potts and stud ends with IS0 261 threads
ends with elastomeric sealing (type El. with elastomeric or metal-to-metal sealing - Part 2:
Stud ends with elastomeric sealing (type El.
IS0 3304:1985, Plain end seamless precision steel
tubes - Technical conditions for delivery.

IS0 3305:1985, Plain end welded precision steel

3 Definitions
tubes - Technical conditions for delivery.
For the purposes of this part of IS0 8434, the defi-
nitions given in IS0 5598 and the following definitions
IS0 3601-3:1987, Nuid systems - Sealing devices
- O-rings - Part 3: Quality acceptance criteria. afwlv.

IS0 4397:1993, Fluid power systems and com- 3.1 fluid power: Means whereby energy is trans-
ponents - Connectors and associated components mitted, controlled and distributed using a pressurized
- Nominal outside diameters of tubes and nominal fluid as the medium.
inside diameters of hoses.
[ISO 55981
IS0 4759-l :I 978, Tolerances for fasteners - Part 7:
Bolts, screws and nuts with thread diameters be- 3.2 connection; fitting: Leakproof device to con-
tween 7,6 (inclusive) and 150 mm (inclusive) and nect pipelines (conductors) to one another, or to
product grades A, B and C. equipment.

[ISO 55981
IS0 5598:1985, Fluid power systems and com-
ponents - Vocabulary.
3.3 fastening thread: Terminal thread of a complete
IS0 61491:1993, Connections for fluid power and fitting.
general use - Ports and stud ends with IS0 261
threads and O-ring sealing - Part 7: Ports with O-ring 3.4 run: Two principal, axially aligned outlets of a tee
seal in truncated housing. or cross.

IS0 6149-2:1993, Connections for fluid power and 3.5 branch: Side outlet(s) of a tee or cross.
general use - Ports and stud ends with IS0 261
threads and O-ring sealing - Part 2: Heavy-duty (S 3.6 chamfer: Removal of a conical portion at the
series) stud ends - Dimensions, design, test meth- entrance of a thread to assist assembly and prevent
ods and requirements. damage to the start of the thread.

IS0 6149-3: 1993, Connections for fluid power and 3.7 assembly torque: The torque to be applied in
general use - Ports and stud ends with IS0 267 order to achieve a satisfactory final assembly.
threads and O-ring sealing - Part 3: Light-duty (1
series) stud ends - Dimensions, design, test meth- 3.8 working pressure: Pressure at which the ap-
ods and requirements. paratus is being operated in a given application.

IS0 8434-l : 1994, Metallic tube connections for fluid [ISO 55981
power and general use - Part 7: 24 degree com-
pression fittings.

IS0 9227:1990, Corrosion tests in artificial atmos- 4 Requirements for materials

pheres - Salt spray tests.
Figure 1 shows the cross-section and component
parts of a typical 24” cone connector with O-ring
weld-on nipple.
 IS0 8434-4:1995(E)

5 Pressure/temperature requirements

5.1 Fittings complying with this part of IS0 8434

made of carbon steel and stainless steel shall meet
or exceed without leakage the requirements of a
vacuum of 6,5 kPa (0,065 bar) absolute pressure up
to the working pressures given in table 1 when used
at temperatures between - 35 “C and + 100 “C.

Weld-on nipple i
5.2 Weld-on nipples in carbon and stainless steel
with different wall thicknesses shall be suitable for
Figure 1 - Cross-section of typical 24” cone
use up to the working pressures given in table 2 when
connector with O-ring weld-on nipple
used at temperatures between - 35 “C and
+ 100 “C.

5.3 Fittings in stainless steel shall be suitable for

use at the working pressures given in tables 1 and 2.
For pressure derating for fittings made of stainless
4.1 Fitting bodies
steel that are to be used at temperatures outside the
ranges given in 5.1 and 5.2, see table3.
Bodies shall be manufactured from carbon steel or
stainless steel that will provide the minimum
pressure/temperature requirements specified in
clause 5. They shall have characteristics that make 5.4 For applications under conditions outside the
them suitable for use with the fluid to be conveyed pressure and/or temperature limits given in table 1
and that will provide an effective joint. Weld-on and in 5.1 to 5.3, the manufacturer shall be consulted.
nipples shall be made of materials classified as suit-
able for welding.
5.5 According to different applications and different
pressure ratings, there are two series of fittings. The
series are referred to as

4.2 Nuts L: light duty

S: heavy duty
Nuts to be used with carbon steel bodies shall be
made of carbon steel and those for use with stainless Ranges of the tube outside diameters and pressure
steel bodies shall be made of stainless steel unless requirements are shown in table 1.
otherwise specified.

5.6 The fitting assembly shall not leak or fail when

hydrostatically tested at four times the applicable
recommended working pressure specified in table 1.
4.3 O-rings Testing shall be conducted at room temperature.

Unless otherwise specified, for use at the pressure

and temperature requirements given in clause 5 and
5.7 The pressure/temperature requirements given
table 1, O-rings for use with fittings in accordance
in tables 1 to 3 and in 5.1 to 5.6 are for weld-on
with this part of IS0 8434 shall be made of NBR
nipples and fitting bodies only. For port and stud end
(nitrile) with a hardness of (90 * 5) IRHD, measured
pressure/temperature requirements, the values
in accordance with IS0 48, and shall conform to the
specified in the respective port and stud end stan-
dimensions given in table 5 and shall meet or exceed
dards and in annex A of this part of IS0 8434 shall
the O-ring quality acceptance criteria for grade N of
wlv.
IS0 3601-3.
IS0 8434-4:1995(E) 0 IS0

6.4 Reducing fittings and reducing elbows shall be

Table 1 - Working pressures for carbon and designated by specifying the larger tube end first.
stainless steel 24” cone connectors with O-ring
weld-on nipples 6.5 Stud fittings shall be designated by specifying
the tube end first, then the thread size for the stud
Tube outside
Working pressure end.
Series diameter’)
mm MPa (bar)
6.6 For tee fittings, the order of designation of the
15 25 (250) connection ends shall be from larger to smaller on the
L 18 to 22 incl. 16 run, followed by the branch end.
(160)
28 to 42 incl. 10 (100)
6.7 For cross fittings, the order of designation of the
6 to 12 incl. 63 (630) connection ends shall be from left to right, followed
S 16 to 25 incl. 40 by top to bottom, with the larger ends on the left and
(400)
at the top.
30 to 38 incl. 25 (250)
NOTE - For higher pressure ratings and for dynamic 6.8 If the fitting has a tube union connection, it shall
conditions, the manufacturer shall be consulted. be designated first, then the designation shall proceed
clockwise.
1) Tube outside diameters per IS0 4397.

6.9 The following letter symbols shall be used:

6 Designation of fittings
Connection end type Letter
6.1 Fittings shall be designated by an alphanumeric Bulkhead BH
code to facilitate ordering. They shall be designated Swivel SW
by IS0 8434-4, followed by a spaced hyphen, then the
Weld-on WD
fitting style letter symbols (see 6.21, followed by a
spaced hyphen, then the series letter (see 5.5) im- Weld-in WI
mediately followed by the outside diameter of the Port P
tube with which they are to be connected, followed
Stud SD
by a multiplication sign (x) then the wail thickness. For
stud ends (connector ends), another spaced hyphen Reducing RE
followed by the thread designation of the stud end
and the sealing type shall be added. Shape Letter
Straight S
EXAMPLE
Elbow E
A straight stud fitting (SDS) for use with tubing of
Tee T
12 mm OD and 2 mm wall thickness, with an
Ml8 x 1.5 stud end in accordance with IS0 6149-2 Run tee RT
(S series), is designated as follows: Branch tee BT
IS0 8434-4 - SDS - S12 x 2 - Ml8 Cross K

Component type Letter

6.2 The letter symbol designation of the fitting style
shall have two parts: the connection end type, im- Nut N
mediately followed by the shape of the fitting. Locknut LN
Nipple NP
6.3 Tube ends are assumed to be male and thus do
not need to be included in the code. However, if an- Examples of compression fittings and designations
other type of end is involved, it shall be designated. are given in figures 2 to 7.
0 IS0 IS0 8434-4:1995(E)

Table 2 - Working pressures for carbon and stainless steel weld-on nipples with various tube wall
thicknesses
Dimensrons In mrllrmetres

Working pressure
Series Tube ODl) 10 MPa 16 MPa 25 MPa 31,5 MPa 40 MPa 63 MPa
(100 bar) (160 bar) (250 bar) (315 bar) (400 bar) (630 bar)
42) e3) 4 e 4 e 4 e 4 e 4 e

15 10 2.5 10 2.5 lo 2,5

18 13 2.5 13 2.5
L 22 17 2.5 I7 2,5
28 23 2.5
35 29 3
42 36 3
6 2.5 1.75 2.5 1.75 2,5 I,75 2,5 1.75 2,5 1.75 2,5 1.75
8 4 2 4 2 4 2 4 2 4 2 4 2
10 6 2 6 2 6 2 6 2 6 2 5 25
12 8 2 8 2 8 2 8 2 7 2.5 6 3
S 16 11 2,5 11 2,5 11 2.5 11 2.5 10 3
20 14 3 14 3 14 3 14 3 12 4
25 19 3 19 3 19 3 17 4 16 4.5
30 24 3 24 3 22 4
38 32 3 32 3 28 5
NOTE - For pressure and/or temperature applications outside those given in this part of IS0 8434, the manufacturer shall
be consulted.

I) OD = outside diameter
2) 4 = tube inside diameter
3) e = tube wall thickness

Table 3 - Pressure deratings for fittings made from stainless steel and used at temperatures outside the
ranges given in 5.1 and 5.2

Working pressure for temperature range

- 35 “C to + 50 “C + 100 “C + 200 “C
MPa (bar) MPa (bar) MPa (bar)

63 (630) 56,1 (561) 50.4 (504)

40 (400) 35.6 (356) 32 (320)
31,5 (315) 28 (280) 25 (250)
25 (250) 22,3 (223) 20 (200)
16 (160) 14.2 (142) 12,8 (‘28)
IO (‘00) 8,9 (89) 8 (80)

NOTE - Intermediate values may be interpolated.

IS0 8434-4: 1995(E)

IS0 8434-4 - S - S20 x 3 IS0 8434-4 - SDS - S20 x 3 - Ml8

Figure 2 - Straight fitting Figure 3 - Straight stud fitting

IS0 8434-4 - S - L22 x 2,5

Figure 4 - Tee

6
8 IS0 IS0 8434-4:1995(E)

7 Requirements for tubes

Carbon steel tubes shall comply with IS0 3304 or
IS0 3305 (cold-drawn and annealed or normalized).
Stainless steel tubes shall comply with IS0 1127
(cold-drawn and annealed or normalized).

8 Across-flats dimensions

8.1 The dimensions across flats for nuts and on the

bodies of the fittings shall be as given in tables 6 to
9. For sizes up to and including 24 mm, tolerances for
across-flats dimensions for forgings shall be -Es mm.
For sizes larger than 24 mm they shall be -y mm.

8.2 Hex tolerances across flats shall be in accord-

ance with IS0 4759-1:1978, product grade C. Mini-
IS0 8434-4 - E - S20 x 3 mum across-corner hex dimensions are 1,092 times
the width across flats. The minimum side flat is 0,43
times the nominal width across flats. Unless other-
Figure 5 - Elbow
wise specified or shown, hex corners shall be
chamfered 15” to 30” to a diameter equal to the width
across flats, with a tolerance of &, mm.

9 Design

9.1 Fittings

The fittings shall conform to the requirements given

in figures 8 to 17 and tables 4 to 10.

9.2 Dimensions
IS0 8434-4 - RESW - S20 x 3 - S12 x 2 Dimensions specified apply to finished parts, including
any plating or other treatments. The tolerance value
Figure 6 - Reducing swivel adaptor for all dimensions not otherwise limited shall be
+ 0,4 mm. The sealing seats of fittings shall be con-
centric with straight thread pitch diameters within
0,25 mm full indicator movement (FIM).

9.3 Passage tolerances

Where passages in straight fittings are machined from

opposite ends, the offset at the meeting point shall
not exceed 0,4 mm. No cross-sectional area at a
junction of passages shall be less than that of the
smallest passage.

9.4 Angular tolerances

IS0 8434-4 - RESD - 520 x 3 - S12 x 2 - G 3/8
A-E Angular tolerances on axis of ends of elbows, tees
and crosses shall be + 2,5” for tube sizes 10 mm and
Figure 7 - Reducing stud fitting less, and t 1,5” for all larger sizes.

7
IS0 8434-4: 1995(E)

9.5 Contour details 11 Manufacture

Details of contour shall be chosen by the manufac-
turer provided the dimensions given in tables 4 to 10 11 .I Workmanship
are maintained. Wrench flats on elbows and tees shall
conform to the dimensions given in the relevant ta- Workmanship shall conform to the best commercial
bles. Abrupt reduction of a section shall be avoided. practice to produce high-quality fittings. Fittings shall
Junctions of small external sections and adjoining be free from visual contaminants, all hanging burrs,
sections that are relatively heavy shall be blended by loose scale and slivers that might be dislodged in use
means of ample fillets. and any other defects that might affect the function
of the parts. All machined surfaces shall have a sur-
face roughness value of R, & 6,3 pm, except where
9.6 Ports and stud ends otherwise specified.

The dimensions of stud ends shall conform to those

given in IS0 6149-2, IS0 11792 or IS0 9974-Z for the 11.2 Finish
S series, and IS0 6149-3, IS0 1179-2 or IS0 9974-2
for the L series. For new designs in hydraulic fluid The external surfaces and threads on all fittings, nuts
power applications, only ports and stud ends in ac- and adaptors, except weld-on fittings and nipples,
cordance with the relevant parts of IS0 6149 shall be shall be protected with an appropriate coating to pass
used. Ports and stud ends in accordance with the a minimum 18-h neutral salt spray test in accordance
relevant parts of IS0 1179 and IS0 9974 shall not be with IS0 9227, unless otherwise agreed upon by the
used for new designs in hydraulic fluid power appli- manufacturer and user. Any appearance of red rust
cations. during the salt spray test shall be considered failure.
Fluid passages shall be excluded from the plating or
coating requirements but shall be protected from rust.
Weld-on fittings and nipples shall be protected from
10 Screw threads corrosion by an oil film or phosphate coating.

10.1 Compression ends 11.3 Shaped fittings

The screw threads on the compression ends of the Shaped fittings up to and including size 12 mm tube
fittings shall be IS0 metric in accordance with outside diameter may be machined from forgings or
IS0 261. barstock. Shaped fittings larger than size 12 mm tube
outside diameter shall be made from forgings.
Threads shall be chamfered at the face of the fitting
to an included angle of 45”. The diameter of the
chamfer shall be equal to the minor diameter of the 11.4 Corners
thread, with a tolerance of & mm.
Unless otherwise noted, all sharp corners shall be
broken to 0,15 mm max.
10.2 Stud ends (connection ends)

The thread for stud ends (connection ends) of fittings 12 Assembly instruction
shall be chosen from IS0 261 (for IS0 6149 or
IS0 9974 stud ends) or IS0 228-l (Class A) (for The assembly of the fittings with the connecting
IS0 1179 stud ends). tubes shall be carried out without external loads.

NOTE 3 Parallel threads require an undercut with a seal- The manufacturer shall draw up assembly instructions
ing washer, O-ring or similar device to ensure a leakproof for the use of the fittings. These instructions shall in-
joint. clude at least the following:

- details relating to the material and quality of suit-

10.3 Thread undercuts and recesses able tubes:

These shall be in accordance with the relevant stud - details concerning the preparation of the selected
end standard. tube;
0 IS0 IS0 8434-4:1995(E)

- instructions regarding the assembly of the fitting, 14 Marking of components

such as the number of wrenching turns or as-
sembly torque. Fitting bodies, weld-on nipples and nuts shall be per-
manently marked with the manufacturer’s name,
trademark or code identifier, unless otherwise agreed
13 Procurement information upon by the user and manufacturer. Nuts shall also
be marked with the tube outside diameter and fitting
The following information shall be supplied by the series.
purchaser when making an inquiry or placing an order:

- description of fitting; 15 Identification statement (Reference to

this part of IS0 8434)
- material of fitting;
Use the following statement in test reports, cata-
- material, outside diameter and wall thickness of logues and sales literature when electing to comply
tube; with this part of IS0 8434:

- fluid to be conveyed; “Dimensions and design for 24” cone connectors with
O-ring weld-on nipples in accordance with
- working pressure; IS0 8434-4:1995, Metallic tube connections for fluid
power and general use - Part 4: 24” cone connec-
- working temperature. tors with O-ring weld-on nipples.”

9
 IS0 8434-4:1995(E)

Dimensrons In mlllimetres,
surface roughness In mlcrometres
Compression end per Tubenutper
IS0 0434-A 7

Tube stop +-

by the manufacturer
O-ring 1

TypeA

Interface is as chosen Tube inside

by the manufacturer

TypeB

Figure 8 - Compression end and weld-on nipple details

10
 IS0 8434-4:1995(E)

Table 4 - Dimensions of weld-on nipples

Dlmenslons In mdhmetres

Series Tube OD
4 4” ( 4 Ll 4

co.20
k O,l -0.05 min. max. max. -t 0.2 f O,l

15 15 10 18 20 17 22 35 28 I,5
18 18 13 21 24 20 23 37 29,5 1,5
22 22 17 25 27 24 24,5 39,5 32 1.5
28 28 23 31 33 30 27,5 42,5 35 1.5
35 35 29 40 42 37,7 30,5 49.5 39 12'
42 42 36 47 49 44.7 30.5 50 39 15'

6 6 23 9 11 7,8 19 32 25 I,1
8 8 4 11 13 93 19 32 25 I,1
10 10 6 14 16 12 20 33,5 26 I,1
12 12 8 16 18 14 20 33.5 26 1.1
16 16 11 20 22 18 26 40.5 32 1,5
20 20 14 24 27 22,6 28,5 47 36,5 18
25 25 19 29 33 27,6 33,5 53,5 41,5 138
30 30 24 35 39 32,7 35,5 57,5 44 13
38 38 32 43 49 40.7 39,5 64,5 48.5 1.8
NOTE - The dimensions given in this table are for the lowest working pressures given in table 2. Refer to table 2 for tube
inside diameters and wall thicknesses required for other working pressures.

1) Maximum permissible inside diameter of type A weld-on nipples. If the inside diameter of a tube is larger than
d + 0.5 mm, use of tvDe B weld-on nioeles is recommended.

11
IS0 8434-4:1995(E)

Figure 9 - O-ring

Table 5 - Dimensions of O-rings

Dimensions In mdimetres

Inside diameter Cross-section

Series Tube OD d, 4
nom. to1. nom. tol.

15 12 & 0,18 2 f 0,09

18 15 f 0,18 2 5 0.09
22 20 rf: 0.22 2 * 0,09
L
28 26 f 0,22 2 5 0.09
35 32 + 0,31 2.5 + 0.09
42 38 * 0,31 25 Ifr 0.09
6 4 + 0,14 1.5 + 0.08
8 6 + 0,14 I,5 + 0.08
10 7,5 + 0,16 I,5 + 0,08
12 9 + 0,16 1.5 + 0.08
s 16 12 & 0,18 2 + 0,09
20 16,3 5 0,18 2,4 &- 0,09
25 20,3 * 0,22 2.4 + 0,09
30 25,3 * 0.22 2.4 + 0.09
38 33,3 f 0.31 24 + 0.09
NOTE - All designs shall meet the performance requirements of this part of IS0 8434 using O-rings to these dimensions.
O-rings of other sizes may be used as long as the sealing function is ensured.

12
 IS0 8434-4:1995(E)

5, across flats s2 ofross fLats

\ I

Elastomer
end per IS0 1179-2 _ L6 (L7) O-ring
or IS0 9974-2 I -
L5
-1
L Thrust wire
1) As chosen by the manufacturer.

Figure 10 - S and L series swivel stud straight adaptor (SWSDS) with stud end per IS0 1179-2 or
IS0 9974-2

13
IS0 8434-4:1995(E) 0 IS0

Table 6 - Dimensions of S and L series swivel stud straight adaptors with stud ends per IS0 1179-2 or
IS0 9974-2
Dlmenslons In mllhmetres

14
0 IS0 IS0 8434-4: 1995(E)

5, across flats s2 across flats

O-ring for IS0 6149-2

stud end

I) As chosen by the manufacturer; see figure 10.

Figure 11 - Swivel stud straight adaptor (SWSDS) with stud end per IS0 6149-2 (S series) or IS0 6149-3
IL series)

Table 7 - Dimensions of swivel stud straight adaptors with stud ends per IS0 6149-2 (S series) or
IS0 6149-3 (L series)
Dimensions In mllllmetiss

Series Tube OD 4 4 d 12 r, r, L7 Sl s-2

+ 0.1 k 0,5 It 02

15 Ml8 x I,5 23.8 10 44 12.5 315 24 27

18 M22 x I,5 26.8 13 44.5 13 31,5 27 32
22 M27 x 2 31.8 17 48.5 16 32,5 32 36
L
28 M33 x 2 40.8 22 51 16 35 41 41 1)
35 M42 x 2 49.8 28 58,5 16 42,5 50 50
42 M48 x 2 54.8 34 64 17,5 46,5 55 60

6 Ml2 x 1.5 16.8 235 38 11 27 17 17

8 Ml4 x I,5 18.8 4 40,5 11 29,5 19 19
10 Ml6 x I,5 21,8 6 44,5 12,5 32 22 22
12 Ml8 x I,5 23,8 8 48 14 34 24 24
S 16 M22 x I,5 26.8 11 52 15 37 27 30
20 M27 x 2 31,8 14 61,5 18.5 43 32 36
25 M33 x 2 40.8 18 66.5 18.5 48 41 46
30 M42 x 2 49,8 23 70 19 51 50 50
38 M48 x 2 54.8 30 81.5 21,5 60 55 60

1) Alternative hex size: 46 mm.

15
 8 IS0
IS0 8434-4:1995(E)

1)
I,
/
..I<
I I

a) Swivel elbow KWE)

s, across flats, tsi

19 I- 19
I- -i

kssflats! PjJ

s2 across tlats s2 across flats

b) Swivel branch tee (SWBT) c) Swivel run tee (SWRT)

I) As chosen by the manufacturer: see figure 10.

Figure 12 - Swivel elbow (SWE), swivel branch tee (SWBT) and swivel run tee (SWRT)

16
 IS0 8434-4: 1995(E)

Table 8 - Dimensions of swivel elbows, swivel branch tees and swivel run tees
Dtmensrons in mrllrmetres

Series Tube OD
4, 42 r, r, 40 41 s, 1) s2

f 0.5 It 0,3 min.

15 12 10 32,5 28 21 9 19 27
18 15 13 35,5 31 23,5 9 24 32
22 19 17 38.5 35 27,5 10 27 36
L
28 24 22 41.5 38 305 10 36 41 2)
35 30 28 51 45 34,5 12 41 50
42 36 34 56 51 40 12 50 60
--
6 4 25 27 23 16 9 12 (14) 17
8 5 4 27,5 24 17 9 14 (17) I9
10 7 6 30 25 17,5 9 17 119) 22
12 8 8 31 29 21,5 9 17 (22) 24
S 16 12 11 36,5 33 24.5 11 24 30
20 16 14 44.5 37 26,5 12 27 36
25 20 18 50 42 30 14 36 46
30 25 23 55 49 35.5 16 41 50
38 32 30 63 57 41 18 50 60

1) Dimensions in parentheses are for fittings manufactured from barstock.

2) Alternative hex size: 46 mm.

17
IS0 8434-4: 7 995(E)

s2 across flats s1 across flats

\ /

O-ring
'1 Lq2 q

I) Aschosenbythemanufacturer;seefigurelO.

Figure 13 - Reducing swivel straight adaptor (RESWS)

Table 9 - Dimensions of L and S series reducing swivel straight adaptors

Dlmenslons In mlllimetres

Working pressure Tube OD d 10 d 12 .52 L 13 s, 1) s, ‘1

Series

MPa (bar) OD OD, zk 03

18 15 12 12 37 9 24 32
16 (160) 15 12 17 41 9
22 27 36
18 15 15 41 9
15 12 22 43 9
28 18 15 22 43 9 32 (36) 41 (46)
22 19 19 45 10
L 15 12 28 46 9
10 (I 00) 35 18 15 28 46 9 41 (46) 50
22 19 28 48 10
28 24 28 48 10
15 12 34 49,5 9
18 15 34 49.5 9
42 22 19 34 51,5 10 50 60
28 24 34 51,5 10
35 30 34 53.5 12
6 IS0 IS0 8434-4:1995(E)

Working pressure Tube OD 40 d 12 L 12 L 13 s, '1 s, 1)

Series

MPa (bar) OD 04 + 085

8 6 4 4 34 9 14 19
6 4 6 34,5 9
63 (630) 10 8 5 5 34,5 9 17 22

6 4 8 37 9
12 8 5 8 37 9 19 24
10 7 7 37 9
6 4 11 39 9
16 8 5 11 39 9 22 30
10 7 11 39 9
12 8 11 39 9
6 4 14 43 9
8 5 14 43 9
20 10 7 14 43 9 27 36
40 (400) 12 8 14 43 9
16 12 12 45 11
6 4 18 45,5 9
S 8 5 18 45,5 9
7
25 10 18 45.5 9 32 (36) 46
12 8 18 45.5 9
16 12 18 47.5 11
20 16 16 49,5 12
6 4 23 51 9
8 5 23 51 9
10 7 23 51 9
30 12 8 23 51 9 41 50
16 12 23 53 11
20 t6 23 55 12
25 20 20 57 14
25 (250) 6 4 30 54.5 9
8 5 30 54.5 9
10 7 30 54.5 9
38 12 8 30 54.5 9 50 60
16 12 30 56,5 11
20 16 30 58,5 12
25 20 30 60.5 14
30 25 30 62.5 16

1) Alternatwe hex size In parentheses.

19
 IS0 8434-4: 1995(E) Q IS0

TubenutperISO8434-1

L See table4 and figure8

Figure 14 - Weld-on reducing nipple (WDRE)

Table 10 - Dimensions of L and S series weld-on reducing nipples

Dimensions In millimetres

Series Working pressure Tube OD 4 e 44 L 15 Ll6 L 17

MPa (bar) OD OD, Ik 0.2 +1 *1

18 15 12 1,5 23 37 29,5 16

16 (160) 18 15 13
22 15 12 1.5 24.5 39,5 32 18

22 18 2
28 18 15 1.5 27.5 42.5 35 21
15 12 I,5
L 28 24 2
10 (100) 35 22 18 2
18 15 185 30,5 49,5 39 25
15 12 1,5
35 31 2
28 24 2
42 22 18 2 30.5 50 39 28
18 15 1-5
15 12 I,5

20
Q IS0 IS0 8434-4:1995(E)

Working pressure Tube OD 4 e L h5 LX L 17

Series

MPa (bar) OD 04 + 02 +I *I
8 6 2 2 19 32 25 11

63 (630) 10 68 32 25
2 20 33,5 26 12

10 4 3
12 8 3 2.5 20 33.5 26 13
6 2 2
12 8 2
16 10 6 2 26 40,5 32 15
8 5 I,5
6 3 1.5
16 10 3
12 8 2
20 IO 6 2 28.5 47 36,5 17
40 (400) 8 5 1.5
6 3 I,5
20 13 3.5
s 16 10 3
25 12 8 2 33,5 53,5 41,5 20
10 6 2
8 5 I,5
6 3 I,5
25 20 2.5
20 16 2
16 12 2
30 12 9 I,5 35.5 57,5 44 22
10 7 1.5
8 5 I,5
6 4 1
25 (250) 30 24 3
25 20 25
20 16 2
38 16 12 2 39,5 64.5 48,5 26
12 9 1.5
IO 7 1.5
8 5 1,5
6 4 1

21
 Q IS0
IS0 8434-4:1995(E)

a) Tube nut(N) b) Straight fitting 6)

c) Elbow (E) d) Tee (T)

e) Cross (K)

Figure 15 - Components for use with weld-on nipples and swivel nut fittings (see IS0 8434-l for
dimensions)

22
0 IS0 IS0 8434-4: 1995(E)

a) Stud fitting (SDS) with stud end b) Stud fitting (SDS) with stud end with
with elastomeric seal per IS0 1179-2 O-ring seal per IS0 6149-2 or IS0 6149-3

c) Bulkhead straight fitting (BHS) d) Locknut (LN)

e) Bulkhead elbow (BHEI

Figure 16 - Components for use with weld-on nipples and swivel nut fittings (see IS0 8434-I for
dimensions)

a) Weld-on bulkhead fitting (WDBH) b) Weld-on straight fitting (WDSI

Figure 17 - Components for use with weld-on nipples and swivel nut fittings (see IS0 8434-l for
dimensions)

23
IS0 8434-4: 1995(E) Q Is.0

Annex A
(normative)

Port and stud end working pressures and combinations of tube outside
diameters and port and stud end thread sizes

See tableA. for values for fluid power applications and general use, and tableA. for values for general use only.

Table A.1 - Values for fluid power and general use

IS0 6149-2 (S series) or IS0 6149-3

IS0 1179-2’)
(L series) with non-adjustable stud ends
Tube OD 4
Series Working Working
Thread Thread
pressure*) pressure*)
mm mm MPa (bar) MPa (bar)

15 10 Ml8 x I,5 25 (250) G lj2A 25 (250)

18 13 M22 x 1,5 16 (160) G1/2A 16 (160)
L 22 17 M27x2 16 (160) G 314 A 16 (160)
28 23 M33x2 10 (I 00) GIA 10 (100)
35 29 M42x2 10 (100) G 11/4A 10 (100)
42 36 M48x 2 10 (I 00) G 11/2A 10 (100)

6 2,5 Ml2 x I,5 63 (630) G l/4A 63 (630)

8 4 Ml4 x I,5 63 (630) G 1/4A 63 (630)
10 5 Ml6 x I,5 63 (630) G 318 A 63 (630)
12 6 Ml8 x I,5 63 (630) G 318 A 63 (630)
S 16 10 M22 x 1,5 40 (400) G 1/2A 40 (400)
20 12 M27x2 40 (400) G 3/4A 40 (400)
25 16 M33x2 40 (400) GIA 40 (400)
30 22 M42x2 25 (250) G 11/4A 25 (250)
38 28 M48x2 25 (250) G 11/2A 25 (250)

NOTE - Working pressures are for those fittings where the smallest 4 (inside diameter) is used. See table 2 for working
pressures for fittings with larger 4 dimensions.

1) Type E with elastomeric sealing.

2) With a design factor of 4 to 1.

24
Q IS0 IS0 8434-4:1995(E)

Table A.2 - Values for general use only

IS0 9974-2’)
Series Tube OD 4
Working
Thread
pressure*)
mm mm MPa (bar)

15 10 Ml8 x 1.5 25 (250)

18 13 M22 x I,5 16 (160)
22 17 M26 x 1.5 16 (160)
L
28 23 M33 x 2 10 (I 00)
M42 x 2 10 (100)
42 36 M48 x 2 10 (100)

6 2,5 Ml2 x 1,5 63 (630)

8 4 Ml4 x I,5 63 (630)
IO 5 Ml6 x 1.5 63 (630)
12 6 Ml8 x I,5 63 (630)

NOTE - Working pressures are for those fittings where the smallest 4
(inside diameter) is used. See table 2 for working pressures for fittings with
larger 4 dimensions.

1) Type E with elastomeric sealing.

2) With a design factor of 4 to 1.

25
IS0 8434-4:1995(E) Q IS0

ICS 23.100.30
Descriptors: hydraulic fluid power, pneumatic fluId power, fluid circuits, pipes (tubes), metal tclbes, hoses, pope joints, pipe frttlngs,
screwed connections, connectors, specifications. manufactunng requirements, dlmenslons. designatton. marking.
Pnce based on 25 pages