A, brinell hardness:Mainly used for determination of castings, forgings, non-ferrous metal parts, hot rolled billet and annealing hardness, measurement range ≯ HB450.Second, the rockwell hardness:HRA is mainly used for high hardness of the specimen, determine the materials and surface hardness hardness is higher than HRC67 above, such as cemented carbide and nitride steel, measurement range HRA > 70.HRC is mainly used for steel parts (such as carbon steel, tool steel, alloy steel, etc.) after quenching and tempering hardness measurement, measurement range HRC20 ~ 67.Three, vickers hardness:Used to measure the hardness and steel parts of the thin, also can be used to determination of carburizing, cyaniding, nitriding, etc. The hardness of surface hardening.Qingdao hexing precision casting stainless steel castings itself properties directly affect the quality of processing, the hardness value is to determine an important indicator of casting processing.