... mechanical property black steel pipe 1)Application: conveyance of gas, petroleum, liquid, and electricity;2)We have engineering team for pipeline system buildingA ... black, blank, bright and galvanizedC: Length of each pipe: 500mm-13,000mmD: Steel grade: st35,st35.8,st37,st37.4,st45,st52 ... 587 etc.DIN2391,DIN2394, DIN17175, EN10210, EN10305 etcAPI,GB black steel pipe for normal and mechanical sturcture