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Use of Products: 10B21,10B28,10B30,10B33 and 10B38 are mainly used to produce fasteners of class 8.8 ~12.9, It has of uniform-chemical composition, low percentage of harmful elements, high purity, slight decarburization, good surface quality, good cold heading performance, low rigidity. They also has characteristics of high intensity and good hardenability after heat treatment. 10B21 gains the gold-cup of the metallurgical product actual quality in 2008. The three steels were identified the lead level of China. 10B21 has been sold the enterprises of the east and the south of China that product the standard parts. And the steel is widely used to product fastener for auto. They have a good reflection.