... Steel TubeType: Tig Welding, Welded,Nitrogen Protection Technology: Cold Rolled, Hot Rolled Standard:ASTM A554-08a AISI GB ... Meterial of Stainless Steel : GP201 202 301 304etc Cold-Rolled 201/304 Stainless Steel Pipe,Austenitis Stainless Steel ... Eddy Current, Hydrostatic Mechanical, Mechanical Test, Chemical Composition Analysis , ISO Quality Management System Certification ,MTC(5) Tolerance:OD: ±0 ...