Minimum load: 

Thrust ball bearing in operation, due to the effects of inertia force, and slippage between the balls and raceways, the temperature rise, work surface damage. In order to prevent the ball rolling road glide, thrust ball bearing must be minimum axial load at work Famin. Famin=A(nmax/1000)2 Type: Famin--the minimum axial load, kN A--the minimum load factor listed in table bearing size.