7306: Tube, pipe of iron or steel, except seamless > 406.4m

730610: Pipe (oil/gas line) iron or steel nes, diameter <406m 730620: Casings,circular, iron/steel, oil/gas drilling <406mm 730630: Pipes etc nes, iron/steel welded nes,diameter <406.4m 730640: Pipes and tubing, stainless steel, welded 730650: Pipes and tubing, alloy steel nes, welded 730660: Hollow profiles/tubes,iron/steel,non-circular, welded 730690: Tube/pipe/hollow profile, iron/steel,riveted/open sea 7306: Tube, pipe of iron or steel, except seamless > 406.4m