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.