Circumferential & point load

Circumferential and point load describe how the load direction moves relative to a bearing ring. If the ring rotates relative to the load, the load zone travels around its entire raceway (circumferential load); if it is stationary relative to the load, the same raceway spot is always loaded (point load). With a rotating shaft and stationary load, the inner ring sees circumferential load and the outer ring point load; rotating unbalance loads reverse this.

This distinction is the key criterion for fit selection: the circumferentially loaded ring needs a tight fit to prevent creep and fretting, while the point-loaded ring may sit looser, easing mounting and allowing axial displacement in floating bearings.