SKF

Precision Lock Nuts (Super-Precision)

SKF precision lock nuts for super-precision bearings are machined to extremely tight thread and face squareness tolerances, ensuring that the bearing inner ring is clamped uniformly without introducing axial runout. The KMT, KMTA, and other precision series feature fine pitch threads for sensitive preload adjustment and locking mechanisms (grub screws or threaded pins) that do not cause ring deformation. These lock nuts are essential for mounting super-precision angular contact ball bearings and cylindrical roller bearings on spindles, where even microns of runout after tightening would degrade machining accuracy. They are balanced for high-speed operation and are supplied with hardened threads to resist wear. Using a precision lock nut is the final, critical step in achieving the full accuracy potential of a super-precision bearing arrangement.