Some suggestions for using PTFE seals

1. The minimum hardness of the shaft should be 55Rc. This hardness requirement applies to all pressure seals and most crankshaft seals. However, in some specific cases, shafts with lower hardness can also be used.

2. The finish of the shaft is generally 10-20CLA, and higher finishes can also be used. This is the opposite of the situation with rubber seals. In rubber seals, if the finish of the shaft is too high, the oil film under the lip contact surface cannot be maintained. PTFE seals are also successfully used to seal rougher shafts (finish is 24CLA). Although the shaft can be processed by any method that can achieve the specified finish, the best is the shaft processed by transverse grinding.

3. The maximum eccentricity between the hole and the shaft is generally 0.88 mm total reading, but the times can be enlarged relative to larger seals.

4. The maximum radial runout of the rotating shaft is also 0.88 mm total reading, and the radial runout value can be larger depending on the speed and diameter of the shaft.