Detailed Explanation of ISO 6431 Pneumatic Cylinder

Introduction

In the field of modern industrial automation manufacturing, pneumatic systems are widely used in the drive and execution parts of mechanical equipment due to their simple structure, quick response, and ease of maintenance. Among the many pneumatic components, the cylinder, as the actuator that directly realizes actuator linear motion, plays a key role in determining the stability and efficiency of the equipment.

To enhance the universality, interchangeability, and standardization of pneumatic cylinders, the International Organization for Standardization (ISO) has established multiple standards. Among them, ISO 6431 is one of the most important standards specifically developed for standard gas cylinder sizes and interfaces. This article will thoroughly analyze the relevant knowledge of the ISO 6431 pneumatic cylinder—from standard definitions to structural parameters, and from applications to series introductions—to comprehensively help you understand the industrial value of this pneumatic component.

What is ISO 6431?

ISO 6431 is an international standard established by the International Organization for Standardization (ISO), which primarily defines the overall dimensions and mounting interfaces of double-acting pneumatic cylinders with detachable end caps and bore sizes ranging from 32 mm to 320 mm.

ISO 6431 Key features include

• Standardized mounting dimensions: The standard specifies exact mounting hole spacing, cylinder body length, and piston rod interface dimensions.

• High interchangeability: Cylinders from different manufacturers can be interchanged across brands when complying with this standard.

• Wide application: The ISO 6431 series is one of the most commonly used medium-to-large pneumatic cylinders in industrial automation today.

Relationship with ISO 15552

Although ISO 6431 is an earlier standard, it was later replaced or integrated by ISO 15552, which expanded the definitions of cylinder mounting accessories and sensor slots, among other structural aspects. However, in industry practice, the term 'ISO 6431' is still widely used to refer to this type of medium-sized cylinder.

Structural Features of ISO 6431 Pneumatic Cylinder

ISO 6431 cylinders are known for their modularity, standardization, and high reliability. Like general pneumatic cylinders, their typical structure includes the following components:

Cylinder Barrel: Typically made of anodized aluminum alloy, offering lightweight properties and corrosion resistance.

Pistons and Rods: The piston drives the piston rod in linear motion. The rod is usually made of hard chrome-plated steel to enhance wear resistance.

End Caps: Designed to be detachable.It is a type of removal of cylinder head，which making maintenance and seal replacement convenient.

Sealing System: Uses polyurethane or nitrile rubber seals, providing excellent sealing performance and durability.

Cushioning Device: Most models are equipped with adjustable cushions to reduce impact and extend service life.

Magnetic Piston: ISO 6431 air cylinder with magnetic piston which support proximity sensor detection for automated control.

Like other pneumatic cylinders, ISO 6431 cylinders include essential components such as the barrel and piston. However, their application scope and technical specifications differ across industries.

Introduction to Technical Parameters of ISO 6431 Pneumatic Cylinder

The ISO 6431 cylinder is renowned for its modularity, standardization, and high reliability. The following is an introduction to its parameters:

After understanding the relevant parameters of the above cylinders, you can fully leverage their advantages in suitable industries and fields.

Application Scenarios And Industry Applications

Due to its high level of standardization and stable performance, the ISO 6431 pneumatic cylinder is suitable for a wide range of automation control applications, including:

Automated Assembly Lines：Used for operations such as clamping, pushing, positioning, and lifting of workpieces.

Packaging Machinery：Acts as a driving mechanism for actions like box opening and closing, coding, and cutting.

Automotive Manufacturing：Enables precise position control in equipment for mixing, spot welding, and assembly.

Food and Pharmaceutical Industries：ISO cylinders made of stainless steel or with corrosion-resistant designs are ideal for clean environments.

Logistics and Material Handling Systems: Facilitates complex motions such as lifting, rotating, and pushing.

If you are in any of the industries above, the ISO 6431 Pneumatic Cylinder is an excellent choice for your applications.

Common Types of ISO 6431 Pneumatic Cylinder

Although ISO 6431 primarily standardizes cylinder dimensions and mounting interfaces, in practice, major pneumatic component manufacturers have developed multiple product series based on this standard. These series, while adhering to the same mounting specifications, differ in structure, performance, and appearance to meet various industrial requirements. Below are four types of ISO 6431 pneumatic cylinders in industrial applications:

DNC Series Cylinders

One of the earliest cylinder types to adopt the ISO 6431 standard, characterized by a rectangular aluminum profile body with a clean and compact appearance. It supports various mounting accessories, and magnetic rings can be added inside the piston for sensor-based control. Commonly used in automated assembly lines and logistics equipment.

DNG Series Cylinders

Widely used by Japanese brands like SMC, this type features a round end cap with tie rod construction, offering a more traditional design and ease of maintenance. It is suitable for heavy-duty and complex working conditions, with strong impact resistance. The design supports multi-position strokes and adjustable cushioning.

SI Series Cylinders

A universal design compatible with both ISO 6431 and ISO 15552 standards. The cylinder body is typically a smooth aluminum alloy tube or a slotted aluminum profile, capable of integrating magnetic sensors. Known for high cost performance, modular design, and component interchangeability, this series is a popular choice for OEM equipment manufacturers.

ISO Standard Series

This series refers to non-brand-specific models strictly designed according to ISO 6431 or ISO 15552 standards. They are often produced by domestic or general-purpose component suppliers. With high compatibility, short lead times, and low cost, they are commonly used in mass production equipment and economical automation lines.

You can have a clearer understanding of the characteristics and advantages of the three types of ISO standards through the following table：

These series of ISO standard cylinders differ in structure, performance, and appearance characteristics while following the same installation interface. You can make a reasonable choice based on your specific needs.

Summarize

ISO 6431 pneumatic cylinders have become an indispensable standard component in industrial automation equipment design due to their high standardization, mature structure, and wide application. Fescolo is the manufacturer that can provide ISO 6431 cylinders. Whether in the selection and design phase or later maintenance process, we can help you understand the principles and advantages behind this standard and make more efficient and reliable technical decisions.

FAQ

Q1. What is an ISO 6431 standard cylinder?

ISO 6431 is a standard developed by the International Organization for Standardization (ISO), which specifies the design and installation specifications for pneumatic cylinders with installation dimensions ranging from 32mm to 100mm. It is suitable for circular cylinder bodies and double acting pneumatic actuators.

Q2. What is the difference between ISO 6431 and ISO 15552?

ISO 15552 is actually an update to ISO 6431, with stronger compatibility and scalability. The installation dimensions of the two are compatible, but ISO 15552 cylinders allow for more functional modules (such as magnetic sensor slots) and are more commonly used in modern industrial automation.

Q3. What is ISO 6431 standard pneumatic cylinder common dimensions?

Common cylinder diameters include: 32mm, 40mm, 50mm, 63mm, 80mm, and 100mm. This is also the size range specified in the standard.