201/301/304 stainless steel square tube standard ASTM A554 Polished,Hariline and Satin GradeMechanical PropertiesTensile StrengthYied ... ,shipbuilding,military use,chemical,automobile exhaust tube and furniture. stainless steel square tube 201stainless steel pipe/tube OD:9.5mm,12.7mm,15 ... .9mm,17mm,18mm,19mm,20mm,22mm,23mm,25mm,28mm,30mm,31 ...