... SteelStructural TubingASTM A501A501Alloy steel tubes for machine purposesJIS G3441SCr420TK, SCM415TK,SCM418TK,SCM420TK,SCM430TK,SCM435TK, SCM440TK,Common structural Carbon steel tubeJIS G3444STK390, STK400 ... , STK500, STK490, STK540Carbon steel pipes for ordinary piping JIS G3452SGPCarbon ...