ISO 11901-1:2025

Overview

ISO 11901-1:2025 - Tools for pressing - Gas springs - Part 1: General specifications defines dimensional, mechanical and identification requirements for gas springs used in press tools. It covers gas springs of type 900 to 100 000, pressurized with nitrogen, with nominal initial forces from 900 N ±5% up to 100 600 N ±5%. The standard specifies metric dimensions, nominal strokes, maximum filling pressures, marking, technical delivery conditions and designation rules to ensure interchangeability and safe use in pressing equipment.

Key topics and requirements

• Scope and types: Applies to gas springs type 900 → 100 000 for press tools, with detailed size and force tables.
• Dimensions & tolerances: Dimensional data (millimetres) and stroke options are given in tables and figures; general manufacturing tolerance is ISO 2768-m.
• Nominal initial force & filling pressure: Initial-force ranges and maximum filling pressures are specified (e.g., certain small types up to 18 MPa, larger types typically up to 15 MPa).
• Gas & pressurization: Gas springs are pressurized with nitrogen; the standard notes location and thread type for the pressure filling inlet - ISO 7‑1 Rp 1/8 for type ≥ 2 500 and M6 for type ≤ 2 500.
• Marking: Gas springs must be indelibly labelled with manufacturer name, gas used, date of manufacture, maximum filling pressure, and type.
• Technical delivery: Supplied at nominal pressure at a reference temperature of 20 °C; the document explains how pressure varies with temperature. Rods should be lightly oiled and protected against shocks.
• Designation: A standard designation format is defined (e.g., Gas spring ISO 11901-1 - 2 500 × 25 - F where “F” indicates inlet location).
• Interchangeability: Detailed figures and tables support mechanical interchangeability across manufacturers.

Applications and users

ISO 11901-1:2025 is essential for:

• Press-tool designers and toolmakers specifying force elements for forming, stamping and molding equipment.
• Gas spring manufacturers ensuring compliant dimensions, threads and marking for market acceptance and interchangeability.
• Maintenance and procurement teams selecting replacement components with correct force, stroke and inlet configuration.
• Compliance officers referencing pressure-equipment requirements (see related directives).

Benefits include improved compatibility across suppliers, clearer procurement specs, safer press-tool design, and streamlined maintenance.

Related standards

• ISO 11901-2 - Specification of mounting accessories for gas springs.
• ISO 7‑1 - Pipe threads (relevant to filling inlet threads).
• ISO 2768‑1 - General linear and angular tolerances.

Keywords: ISO 11901-1:2025, gas springs standard, tools for pressing, press tools, nitrogen gas springs, nominal initial force, pressure filling inlet, marking, technical delivery conditions.