... ,R2,R3 Quality Standard 1. ASTM A 53 Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, ... JIS G3441 Alloy steel tubes for machine purposes4. JIS G3444 Carbon steel tubes for general structural purposes5.DIN 2448 ... , Mechanical Properties (Ultimate tensile strength, Yield strength,Elongation), Technical Properties (Flattening Test, Flaring Test, Bending Test, Hardness Test ...