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-155	3.987	101.27	±.028	±0.71	0.103	2.62	±.003	±0.08
AS 568A-156	4.237	107.62	±.030	±0.76	0.103	2.62	±.003	±0.08
AS 568A-157	4.487	113.97	±.030	±0.76	0.103	2.62	±.003	±0.08
AS 568A-158	4.737	120.32	±.030	±0.76	0.103	2.62	±.003	±0.08
AS 568A-159	4.987	126.67	±.035	±0.89	0.103	2.62	±.003	±0.08
AS 568A-160	5.237	133.02	±.035	±0.89	0.103	2.62	±.003	±0.08
AS 568A-161	5.487	139.37	±.035	±0.89	0.103	2.62	±.003	±0.08
AS 568A-162	5.737	145.72	±.035	±0.89	0.103	2.62	±.003	±0.08
AS 568A-163	5.987	152.07	±.035	±0.89	0.103	2.62	±.003	±0.08
AS 568A-164	6.237	158.42	±.040	±1.02	0.103	2.62	±.003	±0.08
AS 568A-165	6.487	164.77	±.040	±1.02	0.103	2.62	±.003	±0.08
AS 568A-166	6.737	171.12	±.040	±1.02	0.103	2.62	±.003	±0.08
AS 568A-167	6.987	177.47	±.040	±1.02	0.103	2.62	±.003	±0.08
AS 568A-168	7.237	183.82	±.045	±1.14	0.103	2.62	±.003	±0.08
AS 568A-169	7.487	190.17	±.045	±1.14	0.103	2.62	±.003	±0.08
AS 568A-170	7.737	196.52	±.045	±1.14	0.103	2.62	±.003	±0.08
AS 568A-171	7.987	202.87	±.045	±1.14	0.103	2.62	±.003	±0.08
AS 568A-172	8.237	209.22	±.050	±1.27	0.103	2.62	±.003	±0.08
AS 568A-173	8.487	215.57	±.050	±1.27	0.103	2.62	±.003	±0.08
AS 568A-174	8.737	221.92	±.050	±1.27	0.103	2.62	±.003	±0.08
AS 568A-175	8.987	228.27	±.050	±1.27	0.103	2.62	±.003	±0.08
AS 568A-176	9.237	234.62	±.055	±1.40	0.103	2.62	±.003	±0.08
AS 568A-177	9.487	240.97	±.055	±1.40	0.103	2.62	±.003	±0.08
AS 568A-178	9.737	247.32	±.055	±1.40	0.103	2.62	±.003	±0.08
AS 568A-201	0.171	4.34	±.005	±0.13	0.139	3.53	±.004	±0.10