Overview
ISO 21287:2004 defines a metric series of single‑rod pneumatic compact cylinders for pneumatic fluid power systems, rated to a maximum working pressure of 1 000 kPa (10 bar). The standard covers compact cylinder bores from 20 mm to 100 mm, available with or without magnetic piston function. These cylinders are intended for installations where standard cylinder mounting envelopes are too large and where adjustable cushioning is not required.
Key topics and requirements
- Bore sizes covered: 20, 25, 32, 40, 50, 63, 80, 100 mm (in accordance with ISO 3320).
- Maximum working pressure: 1 000 kPa (10 bar).
- Stroke: Nominal strokes follow ISO 4393; maximum recommended stroke length is 500 mm. Nominal stroke tolerances are specified in the standard.
- No adjustable cushioning: The series is deliberately specified without adjustable end‑stroke cushioning; appropriate only for systems that tolerate fixed end conditions.
- Mounting types and dimensions: Includes mounting types per ISO 6099 such as:
- MP4 - cap, detachable plain eyes
- MF1 - head, rectangular flange
- MF2 - cap, rectangular flange
- MS1 - end angles
Detailed basic and mounting dimensions, tolerances and theoretical reference points (TRP) are defined.
- Interchangeability: Cylinders with 20 mm and 25 mm bores use end cover mountings per ISO 21287; bores 32–100 mm can use end cover mountings per ISO 15552.
- Rod end fittings: Piston rod mountings conform to ISO 8139 and ISO 8140.
- Connections and ports: References to port and stud end dimensions per ISO 16030.
- Identification statement: The standard provides a recommended compliance statement for catalogs and test reports.
Applications and users
ISO 21287 compact cylinders are suited to space‑constrained pneumatic systems and where simple, robust linear actuation is required without adjustable cushioning. Typical applications:
- Industrial automation (pick‑and‑place, indexing)
- Packaging and material handling
- Clamp, ejector and positioning devices
- Machine tools and assembly equipment
Primary users:
- Cylinder manufacturers and OEMs specifying interchangeability
- Mechanical and pneumatic system designers
- Procurement and quality engineers validating component dimensions
- Maintenance and service teams replacing parts to standard dimensions
Related standards
Normative references and complementary standards include:
Using ISO 21287:2004 helps ensure dimensional interchangeability, clear mounting definitions, and consistent performance expectations for compact pneumatic cylinders at 10 bar.
