| 摘要 |
PURPOSE:To manufacture an angle steel whose external angle part is almost right angled by forming a projecting part with heating the bent part of a flat metal sheet and forming a right angled external angle part on the projecting part thereof by an angle shaped caliber die. CONSTITUTION:A bent necessary part 10E of a metal flat sheet, i.e., the part to be made in a right angled shape is heated as a 1st stage first. A projecting part 10 is then formed on the heating part by pressing the metal flat sheet from both sides thereof. An intermedium member 1A whose part equivalent to the external angle part in an angle becomes thicker than other parts is then obtained at this stage. At a 2nd stage, then, an external angle part in almost right angled shape is formed at the external angle part by using the caliber die having a desired angle shape. Consequently an angle steel 1 whose external angle part 101 is almost right-angled can be manufactured with good productivity. |
