Sealing surface – mating surface:

The unstamped, hardened and factory-ground faces of antifriction  bearings  or appropriately  machined  shaft collars  and  ends  as  well  as  support  washers,  thrust needlebearing washers or washers stamped from spring sheet or other economical solutions are suitable as the sealing surface. Steel, brass, bronze, aluminium alloys and ceramic can be employed as the materials.

Properties of the sealing surface:

The sealing surface must be perfectly smooth and hard and  may  not  contain  any  spiral  grooves  or  scratches. Surface  hardness  for  steel,  greater  than  HRC  =  40,  or ess for other materials.
Maximum surface roughness for use with oil Rt = 4 µm, or Rt = 10 µm for use with grease.
The radial out-of-true of the sealing surface has no effect on the sealing properties, the permissible axial out-oftrue can – referred to the permissible speed – be up to 0.05mm for use with grease or up to 0.03 mm for use with oil.

Installation tolerances:

The  reception  holes  of  Types  VI  and  DI  should  be fabricatedin  accordance  with  ISA  H  9  and  the  shaft diameterfor Type VA in accordance with ISA h 9.
The  reception  hole  and  the  shaft  must  be  chamfered approx.  150  for  at  least  1  mm.  The  tolerances  for  the functional dimensions of the seals ares shown in the tables

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Installation/assembly:

In most cases “blind installation” is unavoidable, i.e. uniform seating of the sealing lip on the mating surface cannot be checked visually.
Proper installation and assembly can be ensured if the axial shaft seal is inserted flat with the aid of an assembly sleeve or washer, so as to insure that the sealing lip cannot be damaged or distorted. Prior to inserting the seal, clean
and lightly lubricate the sealing surface in order to keep wear to a minimum during in running-in-phase.