Tolerance and beard classes for moulded rubber parts
(For full information please refer to ISO 3302-1)
Fixed and open dimensions
- F = Fixed tool dimensions. Here you can achieve a better tolerance on the finished part compared to "Ö".
- Ö = Open tool dimensions, here you have a larger tolerance, and thus cannot achieve the same tolerances as "F".
Tolerance classes
- M1 - This tolerance class is only used for precision moulded parts. It often requires single-cavity moulds, special rubber compounds and rigorous process control, resulting in very high part prices.
- M2 - Used for moulding parts with high demands. In many cases the same processes are required as used for Mi.
- M3 - Used for moulding parts with 'normal tolerance requirements'.
- M4 - Used for details where dimensions are not so critical.
Tolerance classes
| Nominal size |
M1 |
M2 |
M3 |
M4 |
| About |
Until further notice. |
F ± |
Ö ± |
F ± |
Ö ± |
F ± |
Ö ± |
R&D ± |
| 0 |
4.0 |
0.08 |
0.10 |
0.20 |
0.15 |
0.25 |
0.40 |
0.50 |
| 4.0 |
6.3 |
0.10 |
0.12 |
0.15 |
0.20 |
0.25 |
0.40 |
0.50 |
| 6.3 |
10 |
0.10 |
0.15 |
0.20 |
0.20 |
0.30 |
0.50 |
0.70 |
| 10 |
16 |
0.15 |
0.20 |
0.20 |
0.25 |
0.40 |
0.60 |
0.80 |
| 16 |
25 |
0.20 |
0.20 |
0.25 |
0.35 |
0.50 |
0.80 |
1.00 |
| 25 |
40 |
0.20 |
0.25 |
0.35 |
0.40 |
0.60 |
1.00 |
1.30 |
| 40 |
63 |
0.25 |
0.35 |
0.40 |
0.50 |
0.80 |
1.30 |
1.60 |
| 63 |
100 |
0.35 |
0.40 |
0.50 |
0.70 |
1.00 |
1.60 |
2.00 |
| 10 |
160 |
0.40 |
0.50 |
0.70 |
0.80 |
1.30 |
2.00 |
2.50 |
| 160 |
|
0.3% |
0.4% |
0.5% |
0.7% |
0.8% |
1.3% |
1.5% |
Beard classes
| Class |
Maximum thickness of the beard in mm (S2) |
| X0 |
0 |
No beard |
| X1 |
0.1 |
Precision beard |
| X2 |
0.5 |
Careful beard |
| X3 |
1 |
Normal beard |
| X4 |
2 |
Coarse beard |
| X5 |
Without restriction |
Non-critical beard |
| X0 can only be achieved on surfaces that have no subdivision plane in the tool. |
