... tubeClassSeamless tube/Welded tubeStandardASTM B338,ASTMB 337 ASTMB 381GradeGr1,Gr2,Gr3,Gr7,Gr9,Gr11,Gr12 Gr5*Size: Outer diameter:>=3MMWall thickness:>= 0.5MMLength ... can be made upon request. Pipes with very heavy wall thickness can be made out of round bar, drilled or extruded to size.