D3

D3 is a high-carbon, high-chromium, oil-hardening tool steel that is characterized by a relatively high attainable hardness and numerous, large, chromium-rich alloy carbides in the microstructure. These carbides provide good resistance to wear from sliding contact with other metals and abrasive materials. D3 is deep hardening and exhibits very high compressive strength with excellent stability in heat treatment, holding size almost as well as air-hardening, high-carbon, high-chromium die steels such as D2. It is ideal for tools requiring a combination of hardening accuracy and safety with maximum wear resistance and the greatest possible production.