ISO 3601-2-2016 PDF

Full title and description

Fluid power systems — O-rings — Part 2: Housing dimensions for general applications. This International Standard gives recommended housing (gland/groove) dimensions for ISO 3601 O-rings used in general hydraulic and pneumatic systems (class A and selected class B housings), with provisions for use with and without anti‑extrusion (back‑up) rings.

Abstract

ISO 3601-2:2016 specifies nominal groove widths, depths and clearances for piston, rod and face seals intended for general industrial hydraulic and pneumatic applications. It references O‑ring sizes, cross‑sections and tolerances from ISO 3601‑1 and includes guidance for use with anti‑extrusion (back‑up) rings; Annex A addresses aerospace correlation.

General information

• Status: Withdrawn / superseded (see replacement edition ISO 3601-2:2025).
• Publication date: July 2016 (Edition 2, published 2016‑07).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 23.100.60, 83.140.50 (seals; fluid power systems).
• Edition / version: Edition 2 (2016).
• Number of pages: 54 (ISO published length).

Key lifecycle note: the 2016 edition has been withdrawn and a new edition (ISO 3601-2:2025) has been published to replace it.

Scope

The standard gives recommended housing (gland) dimensions for class A O‑rings for general industrial applications and selected class B housings for common metric hardware (for example cylinder bores and piston rods). It applies to static and dynamic sealing arrangements and provides dimensional tables, tolerances and assembly/usage guidance for housings used with and without back‑up rings. Annex material provides aerospace correlations and additional sizing guidance.

Key topics and requirements

• Recommended gland/groove geometries (width, depth, corner radii, lead‑in chamfers) for piston, rod and face seals.
• Compatibility with ISO 3601‑1 O‑ring size codes, cross‑sections (d1, d2) and tolerances.
• Provisions for use with anti‑extrusion (back‑up) rings and recommended groove allowances when back‑up rings are fitted.
• Guidance on compression, stretch and effective sealing dimensions (percent compression, inside‑diameter stretch, measurement methods).
• Surface finish and run‑out considerations, assembly chamfers and protection of O‑rings during installation.
• Illustrative figures and informative annexes for special applications and aerospace correlation.

Typical use and users

Design and application engineers for hydraulic and pneumatic systems, seal designers and manufacturers, maintenance engineers, and quality engineers use ISO 3601-2 when specifying groove geometry for O‑ring seals in mobile and industrial machinery, cylinders, valves and related fluid‑power components. It is used both in new product design and in standardizing replacement parts and assemblies.

Related standards

ISO 3601-1 (inside diameters, cross‑sections, tolerances and designation codes) is the normative companion for O‑ring sizes and codes; ISO 3601-4 covers anti‑extrusion (back‑up) rings used with O‑rings and is commonly referenced when selecting back‑up ring geometries. The 2016 Part 2 edition has been superseded by a later edition published in 2025.

Keywords

O‑rings, gland dimensions, groove geometry, housing dimensions, back‑up rings, anti‑extrusion, fluid power, hydraulic seals, pneumatic seals, ISO 3601.

FAQ

Q: What is this standard?

A: ISO 3601-2:2016 specifies recommended housing (gland/groove) dimensions for O‑rings used in general hydraulic and pneumatic applications (class A and selected class B housings).

Q: What does it cover?

A: Groove widths, depths, corner radii, chamfers, tolerances and guidance for use with and without anti‑extrusion (back‑up) rings, plus figures and annexes for special correlations (including aerospace).

Q: Who typically uses it?

A: Mechanical, fluid‑power and seal design engineers; manufacturers of hydraulic/pneumatic cylinders and valves; maintenance and quality personnel responsible for seal selection and groove machining.

Q: Is it current or superseded?

A: The 2016 edition has been withdrawn and a newer edition (ISO 3601-2:2025) is available as the replacement; users should consult the 2025 edition for the latest requirements.

Q: Is it part of a series?

A: Yes — ISO 3601 is a multi‑part series for O‑rings. Part 1 defines sizes and tolerances, Part 2 covers housing dimensions, and Part 4 covers anti‑extrusion/back‑up rings; other related parts and amendments provide additional details.

Q: What are the key keywords?

A: O‑rings, gland/groove, housing dimensions, back‑up ring, anti‑extrusion, hydraulic, pneumatic, ISO 3601, seal design.