... Hollow Section Pipe 1.ERW Welded 2.Black Round 3.Manufacturer in Tianjin q235 2.5 inch SCH40 Black Carbon Steel Circular ... : Q195,Q215,Q235,Q235B,Q345B,Grade A/B 2)DN:1/2"-14";WT:0.6-12mm 3)Surface Treatment: ... be the reason that we work together in the future.2.Application: In structure , water pipes,machine manufacture, architecture ... we have stable and fixed cooperators for more than 10 years.