亚洲色图欧美色,久久不射电影,欧美激情手机在线,好看的一级毛片,亚洲狼人区,天天爱天天做天天爽,91欧美日韩

　　Xingtai steel’s XG10B21 products are mainly used in the production of 8.8 bolt. Customers reflects the product composition is stable, high dimensional accuracy. For the free of annealing processing, it can directly reduce the production cost. Because of containing B elements, it has good hardenability. Drawing performance stability, cold heading does not crack, performance stability after heat treatment. The end products made by this material widely used in mechanical fasteners.