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RMA Tolerance Chart

Standard RMA dimensional tolerance classes for molded and extruded rubber products.

Molded products — metric tolerances (± mm)

Nominal dimension		A1 High precision		A2 Precision		A3 Commercial		A4 Basic
Above	Up to	Fixed	Closure	Fixed	Closure	Fixed	Closure	Fixed	Closure
0	10	0.10	0.13	0.16	0.20	0.20	0.32	0.32	0.80
10	16	0.13	0.16	0.20	0.25	0.25	0.40	0.40	0.90
16	25	0.16	0.20	0.20	0.32	0.32	0.50	0.50	1.00
25	40	0.20	0.25	0.32	0.40	0.40	0.63	0.63	1.12
40	63	0.25	0.32	0.40	0.50	0.50	0.80	0.80	1.25
63	100	0.32	0.40	0.50	0.63	0.63	1.00	1.10	1.40
100	160	0.40	0.50	0.63	0.80	0.80	1.25	1.25	1.60
160 & over (multiply by)		—	—	×0.004	×0.005	×0.005	×0.008	×0.008	×0.010

Molded products — inch tolerances (± in)

Nominal dimension		A1		A2		A3		A4
Above	Up to	Fixed	Closure	Fixed	Closure	Fixed	Closure	Fixed	Closure
0	0.40	0.004	0.005	0.006	0.008	0.008	0.013	0.013	0.032
0.40	0.63	0.005	0.006	0.008	0.010	0.010	0.016	0.016	0.036
0.63	1.00	0.006	0.006	0.010	0.013	0.013	0.020	0.020	0.040
1.00	1.60	0.008	0.010	0.013	0.016	0.016	0.025	0.025	0.045
1.60	2.50	0.010	0.013	0.016	0.020	0.020	0.032	0.032	0.050
2.50	4.00	0.013	0.016	0.020	0.025	0.025	0.040	0.040	0.056
4.00	6.30	0.016	0.020	0.025	0.032	0.032	0.050	0.050	0.063
6.30 & over (multiply by)		—	—	×0.004	×0.005	×0.005	×0.008	×0.008	×0.010

Extruded products — cross-section tolerances (± mm)

Above	Up to	E1 High precision	E2 Precision	E3 Commercial
0	1.5	0.15	0.25	0.40
1.5	2.5	0.20	0.35	0.50
2.5	4	0.25	0.40	0.70
4	6.3	0.35	0.50	0.80
6.3	10	0.40	0.70	1.00
10	16	0.50	0.80	1.30
16	25	0.70	1.00	1.60
25	40	0.80	1.30	2.00
40	63	1.00	1.60	2.50
63	100	1.30	2.00	3.20

RMA tolerances depend on the product type and application. When in doubt, ask us — we will confirm the achievable class for your part.

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