An axle nut for preloading a bearing is provided. The axle nut may be used to apply and monitor preload on a bearing or bearing assembly. The axle nut includes a cylindrical body having a first end, a second end having a face adapted to bear against a surface, a longitudinal axis, and an outer surface engagable by a tool; a threaded through-hole directed substantially along the longitudinal axis of the cylindrical body; and at least one recess in the face of the second end of the cylindrical body, the at least one recess adapted to expose at least a portion of the surface the face bears against. The first end of the axle may comprise a nut locking mechanism, for example, the nut locking mechanism may include a counter bore having a plurality of internal projections, such as, gear or spline teeth.