seamless steel pipe: Used in boiler, high press heater, structure,conveying fluid, chemistry, ... : GB3639-2000 and GB8713-88 4. Steel grade: 10#, 20#, 35#, 45#, 40Cr, 37Mn5, 20Cr5. Outer diameter: Φ5.00mm-Φ75.00mm6. Thickness ... customers' requirements8. Packing:In bundle with strip Cold Rolled Precision Seamless Steel Pipe