Cold drawn seamless steel pipe seamless steel pipe is divided and hot rolling, but the surface without any treatment, seamless several points in its material and performance standards, the material of ordinary pipe, alloy tube, the implementation of standards for the 1 structure for seamless steel pipe: GB8162-99 2, the transmission fluid pipe joints sites: GB8163-99 3, boiler seamless steel pipe: GB3087-1999 4, high-pressure boiler seamless pipe: GB5310-95 (ST45.8- ⅲ type) 5, fertilizers, equipment, high pressure seamless steel pipe: GB6479-1999 6, geological drilling seamless steel pipe: YB235-70 7, seamless steel pipe oil drilling: YB528-65 8, petroleum cracking: GB9948 -889, oil drill collar special seamless: YB691-70 10, automobile axle seamless steel pipes: GB3088-1999 11, seamless steel tubes for ship: GB5312-1999 12, drawing cold-rolled precision seamless steel tubes: GB3639-1999 13, all kinds of alloy pipe 16Mn, 27SiMn, 15CrMo, 35CrMo, 12CrMov, 20G, 40Cr, 12Cr1MoV, 15CrMo steel production process according to seamless and welded steel tubes were divided into two categories. Seamless steel pipe is steel ingot, billet or bar made of seamless steel pipe perforated; pipe is hot-rolled or cold rolled steel sheet and strip made of welded, straight seam welded to the vertical, you can spiral welded