O-Ring Size Charts

O-Ring Size Charts

O-ring size charts provide standard dimensions for selecting the correct O-ring based on inner diameter (ID), outer diameter (OD), and cross section (CS). Below you will find common inch and metric O-ring size standards used worldwide.

Standard O-Ring Size Systems

O-rings are manufactured according to international standards to ensure interchangeability and consistent performance.

  • AS568 inch size O-rings (USA standard)
  • Metric O-ring sizes (ISO & DIN based)
  • ISO 3601 international standard O-rings
  • DIN 3771 metric O-rings

AS568 O-Ring Size Chart (Inch Sizes)

The AS568 standard defines inch-sized O-rings commonly used in hydraulic and pneumatic systems in North America.

View AS568 O-Rings →

Metric O-Ring Size Chart

Metric O-rings are measured in millimeters and are widely used in European and international equipment.

View Metric O-Ring Size Chart →

ISO 3601 O-Ring Size Chart

ISO 3601 is an international standard covering dimensions and tolerances for metric O-rings.

View ISO 3601 O-Rings →

DIN 3771 O-Ring Size Chart

DIN 3771 defines commonly used metric O-ring sizes for European industrial applications.

View DIN 3771 O-Rings →

How to Measure an O-Ring

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

Need Help Selecting the Right Size?

If you are unsure about the correct O-ring size, our engineering team can assist you based on drawings, samples, or application requirements.