Tolerances for Metric O-Rings

Due to the fact that there are literally dozens of O-Ring standards globally, finding a single recognized standard for metric O-Ring tolerances is virtually impossible. After extensive research, we have adopted the tolerances shown in the following table, which are based in ISO 3601-1, Class B, Annex A.4. For those sizes not specified in this table, please contact our Customer Service Department, or use the following formula to calculate ID tolerances:

Tolerance = ± [ (ID x 0.95 x 0.009) +.011 ]

CROSS SECTION TOLERANCES (mm)
0. 0 0 to 1. 8 0 ± 0 .0 8
1. 8 1 to 2. 6 5 ± 0. 0 9
2. 6 6 to 3. 5 5 ± 0. 1 0
3. 5 6 to 5. 3 0 ± 0. 1 3
5. 3 1 to 7. 0 0 ± 0. 1 5

Inside Diameter Tolerances (mm)
I.D.	Tol. ±
1.80 to 2.50	0.13
2.51 to 4.50	0.14
4.51 to 6.30	0.15
6.31 to 8.50	0.16
8.51 to 10.00	0.17
10.01 to 11.20	0.18
11.21 to 14.00	0.19
14.01 to 16.00	0.2
16.01 to 18.00	0.21
18.01 to 20.00	0.22
20.01 to 21.20	0.23
21.21 to 23.60	0.24
23.61 to 25.00	0.25
25.01 to 26.50	0.26
26.51 to 28.00	0.28
28.01 to 30.00	0.29
30.01 to 31.50	0.31
31.51 to 33.50	0.32