A method for manufacturing a ferrous rotational member including the steps of turning a first portion of the friction surface at a sufficient feed rate to provide a first deformed layer on the first portion of the friction surface; fine turning a second portion of the friction surface at a sufficient feed rate to provide a second deformed layer on the second portion of the friction surface; burnishing the first and second portions of the friction surface to achieve a predetermined roughness; and nitrocarburizing the rotational member at a time and temperature sufficient for the diffusion of nitrogen atoms and carbon atoms through the deformed layer to form hardened casings having variable thickness. The ferrous rotational member may be that of a brake rotor having a hub surface and a friction surface, where the hub surface and friction surface have a variable thickness hardened casing.