... : 6 to 18mm ( 0.236-0.708 inch) Spiral Steel Pipe(1) Outside Diameter: 219 mm to 2220mm (8 -87 inch ... 0.708 inch) (3) Grade: A, B, X42, X46, X52, X56, X60, X65, J55, (4)Type of Spiral Steel Pipe coating: 2PE, 3PE, ... Epoxy powder. (5) Application: structure Spiral Steel Pipe, piling pipe. Sewage and clear water transpotation. Line pipe for petroleum spiral steel pipe