1)standard:GB,ASTM ,DIN , 2)grade:10#,20#,45#,16Mn,Q235 3)od :2-718mm thickness:1.2-26mm 4)all sizes are supplied ... SPECIFICATIONS1)spiral wels steel pipe as per 10#20#,45#,16Mn 2 ... & material :GB,ASTM , DIN .3) outer diameter :2-718mm.thickness :1.2-26mm,length :5.8m,6m,11m4)method of galvanizeation : cold ...