Roughness of Mating Surface
When deciding on the material to be used and the surface roughness of the mating surfaces, the conditions under which the bearing system is to operate are of considerable importance.
In most cases soft carbon steels with polished surfaces will be adequate.
Roughness measuring units (in accordance to ISO 4288)
|GLYCODUR® F||GLYCODUR® A|
|Ra max||0.4 μm||0.8 μm|
|Rz max||3 μm||6 μm|
For demanding applications, hardened mating surfaces with a minimum surface hardness of 50 HRC or featuring a surface treatment e.g. by hard chrome plating, nickel plating etc. are of great advantage. In these cases, Ra should not exceed 0.3 µm (12 µin) and Rz should not exceed 2 µm (80 µin). Improved surface finishes will improve the running characteristics; poor surface finishes will increase wear.
Roughness Factor c4
This will be taken into account by the roughness factor c4, when designing the bearing.