What is the result of over-tightening a tapered bore bearing's lock nut?

When a tapered bore bearing's lock nut is over-tightened, it leads to decreased bearing clearance. This happens because excessive tightening compresses the bearing and the components surrounding it, resulting in a tighter fit. As the clearance decreases, the fit becomes tighter, which can introduce issues such as increased friction, higher operating temperatures, and potential misalignment.

It's important to maintain the correct bearing clearance for optimal performance. Adequate clearance allows for thermal expansion and the effective distribution of lubricant, which are essential for the longevity and reliability of the bearing assembly. If the clearance is too tight due to over-tightening, it can lead to premature wear and failure of the bearing, thereby reducing the overall efficiency of the machinery in which the bearing is installed.