Oster Professional blades are produced from the finest high carbon steel and handcrafted to our rigorous standards, providing unparalleled precision and performance. Furthermore, our 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.