ISO 21287 Pneumatic Cylinders Guide

Post By: Ryan King On: 15-03-2019 Read Time: 4 minutes - Guides - Pneumatics

Pneumatic cylinders turn compressed air power into a linear movement and force, there are many different designs of a pneumatic cylinder; the most common design consists of moving piston and piston rod contained within a cylinder body, this is commonly referred to as a cylinder with piston rod design and is one of the most widely used pneumatic cylinder designs. Other common pneumatic drives include rodless cylinders that do not have piston rod, rotary indexing tables for rotary motion and stopper cylinders for stopping moving items.

Why Have Cylinders To An ISO Standard?

Pneumatics are a common feature in most industrial environments, and many manufacturers are designing and supplying pneumatic equipment. Pneumatic cylinders make up a large proportion of pneumatic sales globally, and each manufacturer is trying to make as many sales as possible. The competitiveness of the industry is great for designers and end users of equipment giving a wide choice of products.

If every pneumatic manufacturer had their own design of pneumatic cylinder with unique dimensions and mounting options, there would be a vast range of products in the market place, and it would be very unlikely that these would be interchangeable. Manufacturers could design unique features into their cylinders that would prevent them from being swapped and interchanged; this is great for pneumatic manufacturers but not good for end users who may have to change a cylinder, for obsolescence, upgrade or availability.

For these reasons international standards were created for three of the most common types of cylinder designs; round cylinders, standard cylinders and compact cylinders. The international standards provide a set of key metric dimensions, mounting methods and accessories for pneumatic cylinders. The three created standards are:

  • ISO 6432 Round body ISO Cylinder
  • ISO 15552 Standard Cylinder
  • ISO 21287 Compact Cylinder

The international standards created allow users to potentially interchange between manufacturers and ensures users are not restricted to one manufacturer. Nearly every pneumatic manufacturer has a cylinder that adheres to these standards.

ISO 21287 Pneumatic Cylinders Guide

What Is An ISO 21287 Pneumatic Cylinder?

ISO 21287 is the international standard for compact cylinders that are renowned for their compact design and broad area of applications. Compact cylinders are used in applications where the use of standard cylinders is not possible due to their dimensions.

Cylinders adhering to ISO 21287 are a cylinder and piston rod construction contained within a cylinder barrel, unlike ISO 15552 cylinders the cylinder barrel is the same width along the body. Compared to an ISO 15552 cylinder an ISO 21287 can offer up to 50% space saving for the same size bore and stroke length cylinder.

The standard ISO 21287 applies to compact cylinders with a maximum rated pressure of 10bar or 1000 kPA.

  • ISO 21287:2004 Latest Edition
  • ISO 21287:2004 Current being reviewed March 2019
  • Maximum rated pressure of 10bar/ 1000 kPA

ISO 21287:2004 is the current edition for a compact cylinder, and they are currently under review by the international standards community. The standard applies for compact pneumatic cylinders with a piston bore size of 20mm, 25mm, 32mm, 40mm, 50mm, 63mm, 80mm and 100mm, the ISO 21287 references ISO 4393 for the standard nominal stroke lengths; however, the maximum stroke length should not exceed 500mm.

Cylinders Sizes

ISO 21287 states the following piston bore sizes; 20mm, 25mm 32mm, 40mm, 50mm, 63mm, 80mm and 100mm

ISO 21287 standard states the maximum stroke length should not exceed 500mm and references ISO 4393 for the nominal stroke lengths; also, most manufacturers will manufacture a cylinder with any custom stroke length.

Direction Of Movement

ISO 21287 pneumatic cylinders can be supplied with either single or double acting movement. Single acting cylinders only require compressed air for movement in one direction and use a mechanical spring for the other. Single acting cylinders can be either pushing or pulling with the spring mounted in front or behind the piston. A double acting cylinder requires compressed air for both directions of movement.


ISO 21287 standard states that it applies to cylinders not equipped with adjustable pneumatic cushioning. Standard cushioning in an ISO 21287 cylinder is mechanical cushioning rings or pads. However with the introduction of self-adjusting pneuamtic cushioning compact cylinders are now available with this.

What Types Of ISO 21287 Cylinder Are Available?

Rowse Pneumatics have a wide range of ISO 21287 cylinders in stock and available for a quick dispatch. Our range of ISO 21287 cylinders are from leading pneumatic suppliers Festo and Camozzi. Each manufacturer has some different cylinders that adhere to the ISO 21287 standard:

  • Festo ADN Cylinder
  • Festo AEN Cylinders
  • Festo CDC Cylinders
  • Camozzi Series 32 Cylinders

Having different ISO 21287 cylinders allows manufacturers to incorporate different design features and materials to make the cylinders more specific for certain industries or applications. The Festo ADN cylinder is a double acting cylinder to ISO 21287 whereas the Festo AEN is a single acting version. In addition, Festo also has a CDC cylinder that is a clean design, and with corrosive protection built in as standard, this cylinder is designed for the food and beverage environments where these properties are required the standard version would be the Festo ADN or Festo AEN types.

As with most pneumatic cylinders ISO 21287 cylinders can also be supplied with some additional features in addition to simply changing the bore size, stroke length and cushioning. Many manufacturers have further variants to configure the cylinder for the application:

  • Reinforced Piston Rod
  • Through Piston Rod
  • End position locking
  • Heat Resistant Seals
  • Square piston rod
  • Low friction
  • A uniform, slow movement
  • Female piston rods
  • Corrosion protection
  • Different scrapper for seal protection
  • Cold resistant

The flexibility of compact ISO cylinders makes them widely used throughout the world and one of the most popular cylinders Rowse Pneumatics supply.

Are you trying to identify an ISO 21287 pneumatic cylinder? Try our pneumatic cylinder identification tool.