All Derby razor blades are perforated, hardened, and ground by utilizing the most advanced equipment.  All Derby razor blade cutting edges are deposited with chromium-ceramic, tungsten, and platinum by advanced spluttering equipment for optimum edge strength, which provides for a longer shaving lifespan. All Derby razor blades are coated with a polymer for optimum shaving comfort.  From beginning to finished product, all Derby razor blades are subjected to severe quality control inspection at every stage of manufacturing processes by utilization of unique quality control equipment.