The heat treatment of bearings primarily falls into three categories of material selection.  High hardness and compression strength specifications can be met with 52100 alloy steel and 400 series stainless steel.  Both materials may be hardened in atmosphere batch furnaces with oil quench and temper.  The stainless steel materials may also be bright hardened in vacuum and hydrogen furnaces.

High surface hardness specifications may also be met with carburizing and carbonitriding of low carbon steels.  These heat treatments typically achieve surface properties exceeding Rc 60 hardness to case depths of 0.010” to 0.120”.  The core hardness of these parts is in the range of Rc 25 to Rc 50 depending on material selection and heat treating process.

Most bearing heat treatments are accompanied by cryogenic treatment at –120 ^oF to stabilize the parts and to convert soft residual austenite from the quenching process to fully hard martensite.  Most bearings can be finished after heat treatment with glass bead blasting.