If the option ‘Calculate C0w, Cuw using standard stresses’ is set the effective static load capacity C0w is defined as the radial load which leads to pmax = 4200 MPa (or 4000 MPa for roller bearings). The effective fatigue limit is defined similar, but with a stress of 1500 MPa in this case.
For roller bearings edge stresses can occur on high loading leading to different results than usually found in bearing catalogues. Therefor a second option exists for the calculation of effective static load capacity C0w.
If this option is selected the stress in the center of the roller is compared with the permissible stress as above. So edge stresses are not taken into account.
For ball bearings, this option does not affect the results, it only makes a difference for roller bearings.
If the option is set C0w is defined as the radial load which leads to the same maximum roller load than a rigid bearing loaded with Fr = C0. Also for the calculation of Cuw the comparison of roller loading instead of stress is made.
If this option is selected the resulting C0w has the same meaning than C0 for the rigid bearing. It can be useful if own input is used for the static load capacity.