All of Oster blades are put through a 12-step process guaranteeing quality and craftsmanship. We start with a fine-grain carbon steel that is heat treated to create a hard surface for greater wear resistance, leveraging a Rockwell hardness rating of 62. Our patented Cryogen-X process takes the blades down to a -300 deg for a deep freeze, producing a harder, sharper blade which extends the product life. Each blade is then hand lapped for a smooth cut finish.