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-227	2.109	53.57	±.018	±0.46	0.139	3.53	±.004	±0.10
AS 568A-228	2.234	56.74	±.020	±0.50	0.139	3.53	±.004	±0.10
AS 568A-229	2.359	59.92	±.020	±0.50	0.139	3.53	±.004	±0.10
AS 568A-230	2.484	63.09	±.020	±0.50	0.139	3.53	±.004	±0.10
AS 568A-231	2.609	66.27	±.020	±0.50	0.139	3.53	±.004	±0.10
AS 568A-232	2.734	69.44	±.024	±0.61	0.139	3.53	±.004	±0.10
AS 568A-233	2.859	72.62	±.024	±0.61	0.139	3.53	±.004	±0.10
AS 568A-234	2.984	75.79	±.024	±0.61	0.139	3.53	±.004	±0.10
AS 568A-235	3.109	78.97	±.024	±0.61	0.139	3.53	±.004	±0.10
AS 568A-236	3.234	82.14	±.024	±0.61	0.139	3.53	±.004	±0.10
AS 568A-237	3.359	85.32	±.024	±0.61	0.139	3.53	±.004	±0.10
AS 568A-238	3.484	88.49	±.024	±0.61	0.139	3.53	±.004	±0.10
AS 568A-239	3.609	91.67	±.028	±0.71	0.139	3.53	±.004	±0.10
AS 568A-240	3.734	94.84	±.028	±0.71	0.139	3.53	±.004	±0.10
AS 568A-241	3.859	98.02	±.028	±0.71	0.139	3.53	±.004	±0.10
AS 568A-242	3.984	101.19	±.028	±0.71	0.139	3.53	±.004	±0.10
AS 568A-243	4.109	104.37	±.028	±0.71	0.139	3.53	±.004	±0.10
AS 568A-244	4.234	107.54	±.030	±0.76	0.139	3.53	±.004	±0.10
AS 568A-245	4.359	110.72	±.030	±0.76	0.139	3.53	±.004	±0.10
AS 568A-246	4.484	113.89	±.030	±0.76	0.139	3.53	±.004	±0.10
AS 568A-247	4.609	117.07	±.030	±0.76	0.139	3.53	±.004	±0.10
AS 568A-248	4.734	120.24	±.030	±0.76	0.139	3.53	±.004	±0.10
AS 568A-249	4.859	123.42	±.035	±0.89	0.139	3.53	±.004	±0.10
AS 568A-250	4.984	126.59	±.035	±0.89	0.139	3.53	±.004	±0.10
AS 568A-251	5.109	129.77	±.035	±0.89	0.139	3.53	±.004	±0.10