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　　The QML40Cr-B material produced by XINGTAI STEEL is mainly used to produce high strength bolts such as hub bolts, cylinder head bolts and so on. The material has the advantages of high purity of steel, small decarbonization layer and less surface defects. A customer uses our QML40Cr-B to produce hub bolts for passenger cars. The customer responded that our QML40Cr-B material has good hardenability, uniform hardness, high fatigue life, and the quality fully meets the product requirements.