... .fine finish 4.ideal percentage elongation 5.good mechanical property seamless schedule 40 pipe1)Suitable for conveyance of gas, petroleum, liquid, and electricity ... ,st37,st37.4,st45,st52,SAE,grade A,B etc.E: Conforms to international standards, like:Astm A106,179,192,199,200,210 ... ,213,333,335,500,519,556,587 etc.DIN2391,DIN2394, DIN17175, EN10210, EN10305 etc.API ...