The nominal contact angle, ball diameter and radii of races are used to define the positions for centers of curvature in the case of zero clearance.
There are four possibilities to define clearance:
1.Centers of curvature are moved axially. This is only possible for gothic profiles with contact angle larger zero. The maximum clearance that can be achieved is limited.
2.Centers of curvature are moved radially.
3.Centers of curvature are moved in direction of contact angle. This cannot be used in case of contact angle zero.
4.Clearance is generated by reduction of ball diameter. This slightly reduces load capacities as the reduced ball diameter is used for calculation of load capacity.