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Calculating Minimum and Maximum O-Ring Compression

The following formulas can act as a guide for calculating minimum and maximum O-ring compression when designing for sealing applications. The formulas should be used as a guide only. Apple Rubber engineers can assist you in determining exact specifications for your particular application (for more information see Section 12 Formulas in the Seal Design Guide).

O-Ring Compression Calculations for Piston and Bore

Male Radial Seal

*Equations based on maximum O-Ring Cross Section, Minimum Groove depth and filling 90% of the groove.

Legend
A =	Min. Bore Diameter	E =	Max. O-Ring Cross Section
B =	Max. Bore Diameter	F =	Min. O-Ring Cross Section
C =	Min. Groove Diameter	G =	Min. Piston Diameter
D =	Max. Groove Diameter

Concentric		Eccentric

This information is also available in Apple Rubber's MicrOring™ brochure.

O-RING RULE OF THUMB #12

When it is said that an elastomer is good for an application it is meant that some compounds which include that material are acceptable. Not All. For instance, some compounds of EP are good for brake fluid applications, but most are not acceptable. » Learn More