Choosing ISO 6432 round and mini cylinders

What does the ISO 6432 standard cover?

ISO 6432 standardizes single-acting and double-acting round cylinders with small piston diameters, often called mini cylinders. It fixes the piston diameters 8, 10, 12, 16, 20 and 25 mm along with the piston-rod and mounting threads. As a result, cylinders from different makers are largely interchangeable and the mounting parts fit. Larger profile-body drives instead follow ISO 15552.

How do I set piston diameter and stroke?

The piston diameter follows the required force: force equals piston area times working pressure. Add a reserve of about 30 percent so friction, pressure swings and load peaks are covered. The stroke comes from the travel your application needs. Long, thin piston rods buckle under push load, so for a long stroke check the next larger diameter or add a guide.

• Determine the required force and add about 30 percent reserve.
• Pick the piston diameter from push force at real working pressure, not at 10 bar.
• For a long stroke, check rod buckling risk or add a guide unit.
• Use single-acting spring return only for short strokes and a defined home position.

Which mounting and cushioning fits?

The mounting transfers force into the machine and must suit the installation position and side load. ISO 6432 provides threaded stud, flange, swivel eye and clevis as standardized mounting kits. For the end position, cushioning decides service life and noise: elastic cushioning for small masses, adjustable pneumatic cushioning for high speed or large loads.

Frequently asked questions