The carbon tool steels used as cold stamping dies mainly include: T7A, T10A, and T11A, among which T10A steel is the most commonly used. 

T8A steel is rarely used in cold stamping dies. The main reason is that when T8A steel is quenched and heated, there is no excessive carbide in the structure. Even when the heating temperature is relatively low (780~790℃), the crystal grains are easy to grow and are heated by quenching. High sensitivity to overheating, poor toughness in use, and poor wear resistance. The hypereutectoid steels T10A and T11A still retain some residual carbides in the structure after quenching, which can improve the wear resistance of the mold. High strength and certain toughness. This is the reason why the application of T10A steel is more common.

The hypereutectoid steel T12A with a carbon content of more than 1.1% has a lot of surplus carbides, and the particles are coarser, and the carbides are not uniformly distributed in the structure. It is easy to form a network or intermittent network, which improves the mechanical properties of the steel. Go bad. but. For trimming dies and scissors that do not require high toughness and only require high hardness and wear resistance, T12A can still be used.