Precision casting foundry method of precision castings, initial investment are not uniform and productivity, the economic effect Yi also have differences.Therefore, to do more, faster, better, the province, all aspects should give attention to two or morethings arrives.To cope with the selected by casting method carries on the preliminary cost estimate, to determine the economic benefit is high and can ensure the requirements of the casting foundry method.Hardness is a direct impact on machining precision casting is an important indicator of the quality of the work.There are three kinds of precision casting hardness generally, brinell hardness is mainly used to determination of casting, forging, non-ferrous metal parts, the hardness of hot rolled billet and annealing.Rockwell hardness is mainly used for high hardness of the specimen and steel after quenching, or tempering hardness measurement.Vickers hardness is used to determine the hardness and steel parts of the thin, also can be used to determination of carburizing, cyaniding, nitriding, the hardness of surface hardening.