Overview
ISO 11901-4:2021 - Tools for pressing - Part 4: Gas springs with increased spring force and same built height - defines standardized dimensions, nominal initial forces and types of high-force gas springs used in press tools. The standard covers gas springs pressurized with nitrogen, with nominal initial forces from 7 400 N (±5 %) up to 200 000 N (±5 %), types ranging from 7 500 to 200 000, maximum filling pressure 15 MPa, and requirements for marking, technical delivery conditions and designation.
Keywords: ISO 11901-4:2021, gas springs, press tools, nominal initial force, nitrogen, dimensions.
Key topics and technical requirements
- Scope and types: Applies to gas springs with increased spring force and the same built height - types 7 500, 10 000 (nominal force 9 200 N), 15 000, 24 000, 42 000, 66 000, 95 000 and 200 000.
- Nominal forces & tolerances: Nominal initial forces between 7 400 N and 200 000 N with a tolerance of ±5 %.
- Maximum filling pressure: 15 MPa for all specified types.
- End-of-stroke force increase: Coefficient range of 1.5 to 1.8 for end-of-stroke nominal force increase.
- Interchangeability dimensions: Detailed dimensional data (millimetres) and mounting-hole provisions are given in tables and figures; general tolerances follow ISO 2768-m.
- Filling inlet: Pressure filling inlet with pipe thread ISO 7‑1 Rp 1/8.
- Marking: Gas springs must be indelibly labelled with at least manufacturer name, gas used, date of manufacture, maximum filling pressure and type.
- Technical delivery conditions: Supplied at nominal pressure referenced to 20 °C; rod slightly oiled and protected against shocks. Pressure varies with temperature by p = p0 (1 + 0.0036 Δt).
- Designation format: Example - “Gas spring ISO 11901-4 - 24 000 × 25” (type × nominal stroke in mm).
Applications
- Standardizes high-force gas springs used in press tools, stamping, forming and moulding equipment where compact height and high thrust are required.
- Useful for designers specifying reliable, interchangeable gas springs and for manufacturers producing components to fit standard press-tool interfaces.
- Supports maintenance teams selecting replacement gas springs with correct nominal force, stroke and mounting dimensions.
Who should use this standard
- Tool designers and mechanical engineers for press equipment
- Gas spring and press-tool manufacturers
- Quality and procurement teams ensuring interoperability and regulatory compliance
- Maintenance and service technicians replacing or reconditioning press tool gas springs
Related standards
- ISO 11901-2 - Specification of mounting accessories for gas springs
- ISO 2768-1 - General tolerances (ISO 2768-m)
- ISO 7-1 - Pipe threads (Rp 1/8)
- Relevant pressure-equipment regulations (e.g., EU Directive 2014/68/EU)
This summary helps you assess applicability of ISO 11901-4:2021 for specifying, purchasing or manufacturing standardized high-force gas springs for press applications.
