ISO 8434-1 Designation connectors Standard

- Jun 15, 2019-

ISO 8434-1 Connectors shall be designated by an alphanumeric code to facilitate ordering.

They shall be designated by the word “Connector” followed by ISO 8434-1, followed by a spaced hyphen, then the connector style letter symbols, followed by a spaced hyphen, then the series letter(s), immediately followed by the outside diameter of the tube with which they are to be connected.

For weld nipples, a multiplication sign (×) shall then follow, then the tube wall thickness.

There shall be no spaces on either side of the multiplication symbol. For stud ends (connector ends), a multiplication symbol followed by the thread designation of the stud end, followed by a spaced hyphen and the sealing type shall be added.


The letter symbol designation of the connector style shall have three parts: the connection end type, immediately followed by the shape of the connector and by the indication that a complete connector is ordered.


Connection end type Symbol

Bulkhead BH

Swivel with O-ring SWO

Weld-on/weld-in WD

Stud SD

Reducer RD


Shape Symbol

Straight S

Elbow E

45° elbow E45

Tee T

Run tee RT

Branch tee BT

Cross K


Component type Symbol

Nut N

Cutting ring CR

Locknut LN

Nipple NP

Plug PL


Completeness indication Symbol

Complete connector C


Stud end sealing types Symbol

Metal-to-metal sealing B

Elastomeric sealing E

O-ring sealing F


EXAMPLE 1  A stud straight connector, including O-ring without cutting ring and nut, with a heavy-duty stud connection end having an M18 × 1,5 thread in accordance with ISO 6149-2, to be connected to a 12 mm OD tube, is designated for ordering as follows: Connector ISO 8434-1 - SDS - S12×M18 - F



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