RMA Standards for Cross Sectional Tolerance Table — Rubber Extrusions

RMA Standards for Cross Sectional Tolerance Table — Rubber Extrusions

The closer tolerance classes outlined below should not be specified unless required to do so by the final application and they should be restricted to the critical dimensions. The closer tolerances demanded, the tighter the control must be exercised when the material is being extruded and hence the higher the cost incurred.

Dimensions in millimeters

RMA Class		1 – High Precision	2 – Precision	3 – Commercial
Drawing Designations		E1	E2	E3
Above	Up to
0	1.5	±0.15	±0.25	±0.40
1.5	2.5	0.20	0.35	0.50
2.5	4.0	0.25	0.40	0.70
4.0	6.3	0.35	0.50	0.80
6.3	10.0	0.40	0.70	1.00
10.0	16.0	0.50	0.80	1.30
16.0	25.0	0.70	1.00	1.60
25.0	40.0	0.80	1.30	2.00
40.0	63.0	1.00	1.60	2.50
63.0	100.0	1.30	2.00	3.20

Dimensions in inches

RMA Class		1 – High Precision	2 – Precision	3 – Commercial
Drawing Designations		E1	E2	E3
Above	Up to
0.00	0.06	±0.006	±0.010	±0.015
0.06	0.10	0.008	0.014	0.020
0.10	0.16	0.010	0.016	0.027
0.16	0.25	0.014	0.020	0.031
0.25	0.39	0.016	0.027	0.039
0.39	0.63	0.020	0.031	0.051
0.63	0.98	0.027	0.039	0.063
0.98	1.57	0.031	0.051	0.079
1.57	2.48	0.039	0.063	0.098
2.48	3.94	0.051	0.079	0.126

In general, softer materials and those requiring a post cure will need greater tolerances.