Maintenance-free steel/PTFE fabric sliding contact surface combination

The basic rating life can be calculated using

Gh = b1 b2 b4 [Kp / (pn v)]


G = 60 f Gh


Gh=basic rating life, operating hours [h]
G=basic rating service life, number of oscillations
b1=load condition factor (table 1)
b2=temperature factor (diagram 1)
b4=velocity factor (diagram 2)
Kp=constant for the specific bearing load (table 2)
p=specific bearing load [N/mm2]
(for values of p < 5 N/mm2 use p = 5 N/mm2)
n=exponent for the specific bearing load (table 2)
v=mean sliding velocity [m/s]
f=frequency of oscillation [min–1]


Basic rating life calculations consider the influence of the load and sliding velocity. Under very light loads and/or low sliding velocities, the result shows relatively long life. The longer the service life the more important is the influence of contaminants such as dirt, moisture and corrosion. Depending on the operating conditions, accurate life calculations may not be possible.
SKF logo