The diametral clearance Pd is shown for deep groove radial ball bearings, spherical ball bearings, cylindrical roller bearings and spherical roller bearings. It is the distance between the upper and the lower position the inner ring can have without load in a fixed outer ring. For single row bearings it can be calculated as
For pretension, a negative clearance can be entered.
The same value is sometimes described as radial clearance (in contrast to axial clearance), but the measurement is still a difference of diameters.
A -button allows the input of an axial clearance instead of a diametral clearance. For deep groove ball bearings, the clearance can also be calculated for given free contact angle.