High-carbon, high-chromium tool steels A2 and D2 are both known for their outstanding wear resistance and hardness. But the two differ substantially in important ways. Air-hardening tool steel with a low chromium content (5-7%) and a high degree of toughness is known as A2. For tools like punches, dies, and shear blades that need to balance hardness and wear resistance, it is frequently utilised. A high-chromium, high-carbon tool steel called D2 steel, on the other hand, is acknowledged for its remarkable wear resistance and hardness. It is relatively weakly tough and contains 11–13% chromium. Cold work punches and dies are only a couple examples of tooling that frequently uses it and demands a high level of wear resistance. Hence, A2 steel is a good choice for tooling that requires a balance of wear resistance and toughness, while D2 steel is a better option for tooling that requires a high degree of wear resistance.