It is important to note that all o-ring materials shrink to some extent during molding. Over time, certain o-ring materials have been identified as possessing similar shrink rates, and are therefore used as o-ring size standards. The nominal o-ring sizes listed in this catalog are based upon a 70 durometer Nitrile. For o-ring materials other than 70 durometer Nitrile, please contact Apple Rubber, as extensive tooling is available for high shrink compounds.

Standard Tolerances for O-Ring Cross Sections

Cross Section Tolerance ±
Up to .104 .003
.139 .004
.210 .005
.275 .006
.375 .008