T7, T7A hypoeutectoid steel: has good plasticity, toughness and strength, and a certain hardness, can withstand shock and impact loads, but poor cutting ability. Used to manufacture tools that are not subject to impact load, and require appropriate hardness and wear resistance, and good toughness, such as forging dies, chisels, hammers, punches, metal shears, reamers, steel stamps, woodworking Tools, pneumatic tools, machine tool tops, fitter tools, drilling tools, blunt surgical instruments, etc.
T8, T8A eutectoid steel: It is easy to overheat during quenching and heating, the deformation is large, the plasticity and strength are relatively low, it is not suitable to manufacture tools that withstand large impact, but after heat treatment, it has higher hardness and wear resistance. Used to manufacture tools whose cutting edges do not heat up during work, such as woodworking tools, pneumatic tools, fitter tools, simple molds, rivet punches, center hole punches and punches, tools for cutting steel, bearings, cutting tools, aluminum tin alloy Die-casting plates and cores, and various types of springs.