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  The QSCr440-B produced by XINGTAI STEEL has the advantages of stable composition, low harmful elements, small decarbonization layer and so on. It is easy to carry out nodularization annealing, stable heat treatment quality and uniform hardness.It is mainly used in automobile field. A main engine factory uses this product to produce 12.9 grade passenger car bolts, which reflects the stable quality of the product and low cold heading cracking rate.