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-252	5.234	132.94	±.035	±0.89	0.139	3.53	±.004	±0.10
AS 568A-253	5.359	136.12	±.035	±0.89	0.139	3.53	±.004	±0.10
AS 568A-254	5.484	139.29	±.035	±0.89	0.139	3.53	±.004	±0.10
AS 568A-255	5.609	142.47	±.035	±0.89	0.139	3.53	±.004	±0.10
AS 568A-256	5.734	145.65	±.035	±0.89	0.139	3.53	±.004	±0.10
AS 568A-257	5.859	148.82	±.035	±0.89	0.139	3.53	±.004	±0.10
AS 568A-258	5.984	151.99	±.035	±0.89	0.139	3.53	±.004	±0.10
AS 568A-259	6.234	158.34	±.040	±1.02	0.139	3.53	±.004	±0.10
AS 568A-260	6.484	164.69	±.040	±1.02	0.139	3.53	±.004	±0.10
AS 568A-261	6.734	171.04	±.040	±1.02	0.139	3.53	±.004	±0.10
AS 568A-262	6.984	177.39	±.040	±1.02	0.139	3.53	±.004	±0.10
AS 568A-263	7.234	183.74	±.045	±1.14	0.139	3.53	±.004	±0.10
AS 568A-264	7.484	190.09	±.045	±1.14	0.139	3.53	±.004	±0.10
AS 568A-265	7.734	196.44	±.045	±1.14	0.139	3.53	±.004	±0.10
AS 568A-266	7.984	202.79	±.045	±1.14	0.139	3.53	±.004	±0.10
AS 568A-267	8.234	209.14	±.050	±1.27	0.139	3.53	±.004	±0.10
AS 568A-268	8.484	215.49	±.050	±1.27	0.139	3.53	±.004	±0.10
AS 568A-269	8.734	221.84	±.050	±1.27	0.139	3.53	±.004	±0.10
AS 568A-270	8.984	228.19	±.050	±1.27	0.139	3.53	±.004	±0.10
AS 568A-271	9.234	234.54	±.055	±1.40	0.139	3.53	±.004	±0.10
AS 568A-272	9.484	240.89	±.055	±1.40	0.139	3.53	±.004	±0.10
AS 568A-273	9.734	247.24	±.055	±1.40	0.139	3.53	±.004	±0.10
AS 568A-274	9.984	253.59	±.055	±1.40	0.139	3.53	±.004	±0.10
AS 568A-275	10.484	266.29	±.065	±1.40	0.139	3.53	±.004	±0.10
AS 568A-276	10.984	278.99	±.065	±1.65	0.139	3.53	±.004	±0.10