Maintaining proper bore characteristics is important if the integrity of the sealing system is to remain intact. To provide proper fit, the dimensions relative to bore tolerance must be followed. The seal should seat against a counter bore to assure true placement in the bore. For worn or older equipment we suggest a seal with a rubber coated O.D. for higher displacement.
For high thermal expansion environments a ribbed rubber O.D. type seal should be used. Seal types include… SG, TG, VG, KG.
Below is the DIN 3760 standards for bore tolerance.
| BORE TOLERANCE IN INCH | BORE TOLERANCE IN METRIC | ||
| Bore Diameter | Bore Tolerance | Bore Diameter | Bore Tolerance |
| Up to 3.000 | +/-0.001 | Over 6 to 10 | +0.022/-0.000 |
| 3.001 to 6.000 | +/-0.0015 | Over 10.1 to 18 | +0.027/-0.000 |
| 6.001 to 10.000 | +/-0.002 | Over 18.1 to 30 | +0.033/-0.000 |
| 10.001 to 20.000 | +0.002/-0.004 | Over 30.1 to 50 | +0.039/-0.000 |
| 20.001 to 40.000 | +0.002/-0.006 | Over 50.1 to 80 | +0.046/-0.000 |
| 40.001 to 60.000 | +0.002/-0.010 | Over 80.1 to 120 | +0.054/-0.000 |
| Over 120.1 to 180 | +0.063/-0.000 | ||
| Over 180.1 to 250 | +0.072/-0.000 | ||
| Over 250.1 to 315 | +0.081/-0.000 | ||
| Over 315.1 to 400 | +0.089/-0.000 | ||
