Finding the Right O-ring Size


Apple Rubber offers the seal industry’s largest inventory of O-rings, with over 300,000,000 O-rings in stock. With so many options, it may be overwhelming to choose the right size seal for your application.

One of our most frequently asked questions is the difference between AS568 designations. AS568 numbers were established in a document originally published by the SAE (Society of Automotive Engineers). These O-rings are generally considered to be the U.S. size standard. You may notice different AS568 designations, but there is no difference between the AS568A, AS568B, and AS568C designations.

For more information on O-ring sizes or for help finding the right seal for you, check out our O-ring size search tool or contact us today.