ISO/FDIS 13726

Hydraulic fluid power - Single rod cylinders, 16 MPa (160 bar) compact series with bores from 250 mm to 500 mm - Accessory mounting dimensions

ISO 13726:2008 specifies the mounting dimensions required for interchangeability of accessories for 16 MPa (160 bar) compact cylinders conforming to ISO 6020-3. The accessories have been designed specifically for use with cylinders manufactured in accordance with ISO 6020-3, but this does not limit their application. ISO 13726:2008 covers the following accessories: AP2 – rod clevis, female thread (see Figure 1 and Table 1); AP4 – rod eye, plain, female thread (see Figure 2 and Table 2); AA4 – L – pivot pin (locking plate) (see Figure 3 and Table 3); AL6 – locking plate for pivot pin (see Figure 4 and Table 4); AA4 – S – plain pivot pin (see Figure 5 and Table 5).

Transmissions hydrauliques — Vérins à simple tige, série compacte 16 MPa (160 bar) d'alésages 250 mm à 500 mm — Dimensions d'interchangeabilité des accessoires

L'ISO 13726:2008 spécifie les dimensions nécessaires à l'interchangeabilité des accessoires des vérins compacts 16 MPa (160 bar) conformes à l'ISO 6020-3. Les accessoires ont été conçus spécifiquement pour être utilisés avec les vérins fabriqués conformément à l'ISO 6020-3, mais ne se limitent pas à cette application. L'ISO 13726:2008 couvre les accessoires suivants: AP2 – chape taraudée, filetage femelle; AP4 – tenon taraudé, filetage femelle; AA4 - L – axe d'articulation (plaque d'arrêt); AL6 – plaque d'arrêt pour axe d'articulation; AA4 - S – axe d'articulation lisse.

General Information

• Status: Not Published
• ICS: 23.100.20 - Cylinders
• Technical Committee: ISO/TC 131/SC 3 - Cylinders
• Drafting Committee: ISO/TC 131/SC 3 - Cylinders
• Current Stage: 5000 - FDIS registered for formal approval
• Start Date: 27-Nov-2025
• Completion Date: 28-Nov-2025

Relations

• Revises: ISO 13726:2008 - Hydraulic fluid power - Single rod cylinders, 16 MPa (160 bar) compact series with bores from 250 mm to 500 mm - Accessory mounting dimensions
• Effective Date: 18-Mar-2023

Overview

ISO/FDIS 13726 (ISO 13726:2025) defines accessory mounting dimensions for single‑rod hydraulic cylinders in the 16 MPa (160 bar) compact series with bores from 250 mm to 500 mm. The standard establishes the dimensional interfaces needed for interchangeability of common cylinder accessories when used with cylinders conforming to ISO 6020‑3. It replaces the 2008 edition and clarifies accessory types, designation rules and application instructions for reliable mechanical connection.

Key topics and requirements

• Scope and accessory types: mounting dimensions for accessories identified in ISO 6099:
  • AP2 – rod clevis, internal thread
  • AP4 – rod eye, plain, internal thread
  • AA4‑L – pivot pin (locking plate)
  • AL6 – locking plate for pivot pin
  • AA4‑S and AA4‑R – plain pivot pins (split‑pin and snap‑ring types)
• Dimension tables and figures: detailed figures (Figure 1–6) and tables (Table 1–5) give nominal sizes, thread forms, clearances and key dimensions (e.g., KK, CK, CV, NT) for bores 250–500 mm.
• Load basis: accessory design is based on maximum forces derived from nominal pressures and bore diameters per ISO 2944 and ISO 3320; cross‑sections must be sized to withstand maximum tensile load.
• Tolerances and fits: recommended tolerance for plain bearing pins is f8 in accordance with ISO 286‑2; specific hole/shaft tolerances and limits are provided in the tables.
• Installation and maintenance:
  • Rod clevis (AP2) and rod eye (AP4) must be screwed firmly against the piston‑rod shoulder before locking.
  • Adequate lubrication and lubrication intervals depend on operating conditions.
• Designation and identification: accessories are designated by ISO 6099 mounting code followed by “ISO 13726” and the type number; a recommended identification statement is provided for catalogs and test reports.
• Notable updates: third edition adds accessory code AA4‑R, modifies figures/tables, and aligns designation with ISO 8132/8133.

Applications and users

ISO 13726 is essential for:

• Hydraulic cylinder manufacturers and accessory suppliers ensuring interchangeability
• OEMs and machine designers specifying mounting interfaces for hydraulic actuators
• Maintenance engineers and service shops selecting replacement accessory parts
• Procurement and technical spec writers producing catalogs, drawings and test reports

Keywords: ISO 13726, hydraulic cylinders, accessory mounting dimensions, ISO 6020‑3, AP2, AP4, AA4, AL6, 16 MPa, 160 bar, 250–500 mm.

Related standards

• ISO 6020‑3 - Mounting dimensions for single rod cylinders (compact series)
• ISO 6099 - Identification code for mounting types
• ISO 5598 - Fluid power vocabulary
• ISO 286‑2 - Tolerance classes (holes and shafts)
• ISO 2944, ISO 3320 - Pressure and bore/rod sizing references
• ISO 24652 - Rod eyes with spherical bearings

Standards Content (Sample)

FINAL DRAFT
International
Standard
ISO/TC 131/SC 3
Hydraulic fluid power — Single
Secretariat: DIN
rod cylinders, 16 MPa (160 bar)
Voting begins on:
compact series with bores from
2026-01-05
250 mm to 500 mm — Accessory
Voting terminates on:
mounting dimensions
2026-03-02
Transmissions hydrauliques — Vérins à simple tige, série
compacte 16 MPa (160 bar) d'alésages 250 mm à 500 mm —
Dimensions d'interchangeabilité des accessoires
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
FINAL DRAFT
International
Standard
ISO/TC 131/SC 3
Hydraulic fluid power — Single
Secretariat: DIN
rod cylinders, 16 MPa (160 bar)
Voting begins on:
compact series with bores from
2026-01-01
250 mm to 500 mm — Accessory
Voting terminates on:
mounting dimensions
Transmissions hydrauliques — Vérins à simple tige, série
compacte 16 MPa (160 bar) d'alésages 250 mm à 500 mm —
Dimensions d'interchangeabilité des accessoires
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2026
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Accessory mounting dimensions . 1
5 Requirements for cross-sections . 2
6 Application instructions . 2
6.1 General requirement .2
6.2 Installation .2
6.3 Lubrication .2
7 Designation . 2
8 Identification statement (reference to this document) . 2
Bibliography . 8

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO 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. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 131, Fluid power systems, Subcommittee SC 3,
Cylinders.
This third edition cancels and replaces the second edition (ISO 13726:2008), which has been technically
revised.
The main changes are as follows:
— Accessory with code of AA4-R has been added in the Scope;
— List of standards has been updated in Clause 2;
— 4.2 has been replaced by a Note;
— Clause 5 has been updated to delete the requirement on yield strength of the material;
— A new subclause 6.1 has been added;
— Designation format in Clause 7 have been changed to align with ISO 8132 and ISO 8133;
— Figure 1 to Figure 4 have been modified;
— Dimension NT has been added in Table 1 and Table 2;
— Dimension CV has been changed to a reference dimension in Table 1 an
...

ISO /TC 131/SC 3/WG 1
Secretariat: DIN
Date: 2025-12-062026-xx
Hydraulic fluid power — Single rod cylinders, 16 MPa (160 bar)
compact series with bores from 250 mm to 500 mm — Accessory
mounting dimensions
Transmissions hydrauliques — Vérins à simple tige, série compacte 16 MPa (160 bar) d'alésages 250 mm à 500
mm — Dimensions d'interchangeabilité des accessoires
FDIS stage
Voting begVoting beginins s on:on: 20202626--0101--0101
Voting termiVoting terminatesnates on: on:

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
at the address below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
EmailE-mail: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents
Foreword . iv
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Accessory mounting dimensions. 1
5 Requirements for cross-sections . 2
6 Application instructions . 2
6.1 General requirement . 2
6.2 Installation . 2
6.3 Lubrication . 2
7 Designation . 2
8 Identification statement (reference to this document) . 2
Bibliography . 10

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO 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. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 131, Fluid power systems, Subcommittee SC 3,
Cylinders.
This third edition cancels and replaces the second edition (ISO 13726:2008), which has been technically
revised.
The main changes are as follows:
— — Accessory with code of AA4-R has been added in the Scope;
— — Documents lists haveList of standards has been updated in 2the normative references;;
— — 4.2 has been replaced by a Note;
— 5— Clause 5 has been updated to delete the requirement on yield strength of the material;
— — A new 6.1subclause 6.1 has been added;
— — Designation format in 7Clause 7 have been changed to align with ISO 8132 and ISO 8133;
— 0— Figure 1 to 0figure 4 have been modified;
— — Dimension NT has been added in 0Table 1 and 0Table 2;;
— — Dimension CV has been changed to a reference dimension in 0Table 1 and 0Table 2;;
— — Unit of the nominal force has been changed to kN in 0Table 1 to 0Table 5;;
iv
— 0— Figure 6 have been added for accessory type AA4-R.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
Introduction
In hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure within
an enclosed circuit.
One component of such systems is the fluid power cylinder. This is a device that converts hydraulic power into
linear mechanical force and motion. It consists of a movable element, i.e. a piston and piston rod, operating
within a cylindrical bore.
vi
Hydraulic fluid power — Single rod cylinders, 16 MPa (160 bar)
compact series with bores from 250 mm to 500 mm — Accessory
mounting dimensions
1 Scope
This document specifies the mounting dimensions of the accessories regarding interchangeability for 16 MPa
(160 bar)
...