AN Fitting O-Ring Reference Chart

The following chart outlines the proper O-ring sizes that should be used in “AN” O-ring Boss Fittings.

C&R Racing recommends the use of Buna-N (Nitrile) O-rings
for most cooling systems applications. For extreme temperature applications we suggest using Viton O-rings.
Upon installation always remember to lubricate the o-ring and check for damage.

AN Size
Thread Size
O-ring Size
-3
3/8-24
2-011
-4
7/16-20
2-012
-6
7/16-20
2-013
-8
3/4-16
2-016
-10
7/8-14
2-115
-12
1 1/16-12
2-119
-16
1 5/16-12
2-122
-20
1 5/8-12
2-128