Tolerances for soft rubber parts according DIN7715
The draughtsmen, technician or constructor considering an application of technical rubber should study the German standard sheet DIN 7715. The size tolerances mentioned here are observed by all rubber manufacturers. The smallest tolerances useable for soft rubber parts are mainly determined by the manufacturing process. The tolerance groups in the table concern the following manufacturing processes. With tolerances in one direction, so only + or only -, the tolerance figure in the table must be doubled. So instead of 0.3 = + 0.6 or another limitation, e.g. + 0.2 - 0.4.
Tolerance group II (rough tolerances) for:
- Wall thicknesses of wound hoses with and without inlays.
Tolerance group II (medium-fine tolerances) for:
- Moulded parts such as profile flex and hose.
- Internal diameters of wound hoses with and without inlays (sometimes tolerance group I).
Tolerances
| Sizes in mm |
Group II |
Group III |
Group I |
|---|---|---|---|
| 0 - 3 |
± 0,4 |
± 0,3 |
± 0,2 |
| 3- 6 |
± 0,5 |
± 0,4 |
± 0,2 |
| 6 - 10 |
± 0,6 |
± 0,5 |
± 0,3 |
| 10 - 18 |
± 0,8 |
± 0,6 |
± 0,3 |
| 18 - 30 |
± 1 |
± 0,8 |
± 0,4 |
| 30 - 50 |
± 1,5 |
± 1 |
± 0,5 |
| 50 - 80 |
± 2 |
± 1,2 |
± 0,6 |
| 80 - 120 |
± 2,5 |
± 1,4 |
± 0,8 |
| 120 - 180 |
± 3 |
± 1,6 |
± 1 |
| 180 - 250 |
± 4 |
± 2 |
± 1,3 |
| 250 - 315 |
± 5 |
± 2,5 |
± 1,6 |
| 315 - 400 |
± 6 |
± 3 |
± 2 |
| 400 - 500 |
± 7 |
± 3,5 |
± 2,5 |
| 500 |
± 1,5% |
± 8,0% |
± 0,5% |
