O-rings: AS568 standard and non-standard sizes
Specialty Seal manufactures and distributes O-rings in AS568 standard sizes and non-standard dimensions, in dozens of commercial and special elastomer compounds.
AS568 standard sizes
Most O-rings are called out by an AS568 "dash number." The standard defines 369 sizes, from .029" ID × .040" CS up to 25.940" ID × .275" CS. Most sizes fall in five common cross-sections: .070", .103", .139", .210" and .275".
| Dash series | Nominal cross-section | Metric equivalent (approx.) |
|---|---|---|
| -001 to -050 | .070" | 1.78 mm |
| -102 to -178 | .103" | 2.62 mm |
| -201 to -284 | .139" | 3.53 mm |
| -309 to -395 | .210" | 5.33 mm |
| -425 to -475 | .275" | 6.99 mm |
| -901 to -932 | varies | Tube-fitting boss seals |
Non-standard and special O-rings
Hundreds of non-standard O-ring sizes are available from existing tooling. Our stock of O-rings covers most standard sizes in dozens of commercial and special compounds. Send the dimensions, material or specification and quantity for a quote.
How an O-ring seals
An O-ring seal is an O-ring installed in a gland (groove). Compressing the cross-section against the mating surface closes the passage and stops fluid or gas from escaping. O-rings are also used as drive belts, bumpers and spacers.
Request a quote
Send your drawing number, material or specification, quantity and required date. We reply by phone or email.
Specialty Seal Co., Inc.1308 W. Magnolia Blvd.
Burbank, CA 91506
Commercial and industrial accounts only. No walk-in, retail or small-quantity orders.