... type of GB, ASTM, AISI, ASME, DIN, BS, EN, etc. According to customers' different requirements. (7). Main material are CK45, AISI 4140&4130 ... the third party inspection, we will try out utmost to satisfy our customers' request. (12). If you have office in China, pls kindly ... pay a visit to our factory, and we are with much pleasure to ...