Buna-N Back-Ups 90 Durometer Rings

• O-Ring Sizing Chart (PDF)
• O-Ring Material Guide (PDF)

Master Item #	Actual Size I.D. (in)	Actual Size I.D. (mm)	Actual Size I.D. Tolerance (in)	Actual Size I.D. Tolerance (mm)	Actual Size W. (in)	Actual Size W. (mm)	Actual Size W. Tolerance (in)	Actual Size W. Tolerance (mm)
AS 568A-376	9.725	247.02	±.055	±1.40	0.21	5.33	±.005	±0.13
AS 568A-377	9.975	253.37	±.055	±1.40	0.21	5.33	±.005	±0.13
AS 568A-378	10.475	266.07	±.060	±1.52	0.21	5.33	±.005	±0.13
AS 568A-379	10.975	278.77	±.060	±1.52	0.21	5.33	±.005	±0.13
AS 568A-380	11.475	291.47	±.065	±1.65	0.21	5.33	±.005	±0.13
AS 568A-381	11.975	304.17	±.065	±1.65	0.21	5.33	±.005	±0.13
AS 568A-382	12.975	329.57	±.065	±1.65	0.21	5.33	±.005	±0.13
AS 568A-383	13.975	354.97	±.070	±1.78	0.21	5.33	±.005	±0.13
AS 568A-384	14.975	380.37	±.070	±1.78	0.21	5.33	±.005	±0.13
AS 568A-385	15.955	405.26	±.075	±1.91	0.21	5.33	±.005	±0.13
AS 568A-386	16.955	430.66	±.080	±2.03	0.21	5.33	±.005	±0.13
AS 568A-387	17.955	456.06	±.085	±2.16	0.21	5.33	±.005	±0.13
AS 568A-388	18.955	481.41	±.090	±2.29	0.21	5.33	±.005	±0.13
AS 568A-389	19.955	506.81	±.095	±2.41	0.21	5.33	±.005	±0.13
AS 568A-390	20.955	532.21	±.095	±2.41	0.21	5.33	±.005	±0.13
AS 568A-391	21.955	557.61	±.100	±2.54	0.21	5.33	±.005	±0.13
AS 568A-392	22.94	582.68	±.105	±2.67	0.21	5.33	±.005	±0.13
AS 568A-393	23.94	608.08	±.110	±2.79	0.21	5.33	±.005	±0.13
AS 568A-394	24.94	633.48	±.115	±2.92	0.21	5.33	±.005	±0.13
AS 568A-395	25.94	658.88	±.120	±3.05	0.21	5.33	±.005	±0.13
AS 568A-425	4.475	113.67	±.033	±0.84	0.275	6.99	±.006	±0.15
AS 568A-426	4.6	116.84	±.033	±0.84	0.275	6.99	±.006	±0.15
AS 568A-427	4.725	120.02	±.033	±0.84	0.275	6.99	±.006	±0.15
AS 568A-428	4.85	123.19	±.033	±0.84	0.275	6.99	±.006	±0.15
AS 568A-429	4.975	126.37	±.037	±0.94	0.275	6.99	±.006	±0.15