440C stainless steel carbon content of C-1.2% this rust resistant steel is good, is more commonly used mass production and imported stainless steel knife, its chromium content up to 16-18%, also the first one tool for making stainless steel, popular. If, as stainless steel bearings for heat treatment is generally recommended before tempering operations cryogenic treatment. Such cryogenic treatment increased the hardness of the processing of steel, increased wear resistance, and dimensional stability. Therefore, cryogenic treatment 440C, and are often used on the tool heat treatment. Features: high hardness and wear resistance of medium, when polished, its disadvantage is the relatively large viscosity and temperature quickly. Suggested the use of chromium corundum or microcrystalline corundum grinding wheel for grinding. 440C annealing temperature is very low, as a tool and bearing heat treatment time, hardness can usually reach HRC57-59, if carried out cryogenic treatment, the hardness can reach HRC59-61. Corrosion resistance and toughness are strong, now more widely used in high-quality hand-made knife and tool manufacturing plant.