AS568 O-Ring Size Chart

The AS568 O-ring size chart defines standard inch dimensions for O-rings used in hydraulic, pneumatic, and industrial sealing applications. This standard is widely adopted in North America and ensures compatibility across manufacturers.

What Is AS568 O-Ring Standard?

AS568 is a dimensional standard established by SAE for inch-sized O-rings. Each AS568 O-ring size is identified by a three-digit dash number (for example, -214 or -325), which corresponds to a specific inner diameter (ID) and cross section (CS).

• Standardized inch dimensions
• Interchangeable across manufacturers
• Commonly used in hydraulic and pneumatic systems
• Available in a wide range of elastomer materials

AS568 O-Ring Size Chart Overview

The AS568 size system is divided into several series based on cross section:

• AS568-0XX series
• AS568-1XX series
• AS568-2XX series
• AS568-3XX series
• AS568-4XX series

Each dash number represents a unique combination of inner diameter (ID), outer diameter (OD), and cross section (CS).

How to Measure AS568 O-Rings

• Measure the inner diameter (ID) using a caliper
• Measure the cross section (CS)
• Calculate the outer diameter (OD = ID + 2 × CS)

Available Materials for AS568 O-Rings

AS568 O-rings can be manufactured in various elastomer compounds to suit different operating environments:

• NBR (Buna-N) O-Rings
• FKM (Viton®) O-Rings
• EPDM O-Rings
• Silicone O-Rings
• FFKM O-Rings

Common Applications

• Hydraulic sealing systems
• Pneumatic cylinders and valves
• Automotive fluid sealing
• Industrial machinery

Custom AS568 O-Rings & Bulk Supply

We manufacture AS568 O-rings in standard and custom materials, hardness, and colors. OEM and bulk supply services are available for industrial customers worldwide.

Looking for finished products? Visit our AS568 O-Rings product page for available sizes and materials.