Oster Professional blades are produced from the finest high-carbon steel and handcrafted to rigorous standards providing unparalleled precision and performance. Furthermore U.S.-made blades are hardened to RC62-66 (Rockwell Scale C) in-house prior to receiving a cryogenic treatment which further enhances the hardening process. The blade-cutting surfaces are then sharpened finished and tested with proven Oster® proprietary processes ensuring ultra-sharp blades that continue to stand the test of time.