Housing bore requirements
To reduce the risk of seal damage during installation, the housing bore should have a 15 to 30° lead-in chamfer. The chamfer should be free of burrs and the transition radius r between the seal seat and shoulder should be in accordance with the recommendations in the table.
The depth of a metric housing bore B for metal-cased or metal-inserted seals should be at least 0,3 mm (0.012 in.) larger than the nominal seal width b (fig 1). The corresponding values for an inch housing bore B are 0.016 in. (0,4 mm).
Seals without metal reinforcement are manufactured oversized relative to the housing bore diameter and depth to enable proper compression and stability. The actual seal width is approximately 0,4 to 0,8 mm (0.016 to 0.032 in.) wider than the bore depth B. For all-rubber HS seals, the bore depth tolerance should be ±0,13 mm (0.005 in.) and ±0,10 mm (0.004 in.) for fabric-reinforced HSF seals.
In order to facilitate seal removal, holes in the housing shoulder (A) can be incorporated during the design stage (fig 2).