| 摘要 |
PURPOSE:To obtain a screw with high strength, while the management of the dimensional accuracy of a stock is easily achieved by a method in which the stock is pressed so that its side is pushed against a molding face, and the molded object in which the screw thread of half periphery is molded on the side is made, and then two molded objects are integrally combined and fixed, thereby to molde the screw. CONSTITUTION:A stock 3 is cut into a prescribed length, and it is inserted into a mold and then is softened under heating. The stock is pressed so that its side is pushed against a molding face with a press ram 12. Thus, the molded object 14 in which the screw tread 13 of half periphery is molded on its side, is obtained. Next, the molded object 14 is softened under cooling, and if unnecessary, part 14a is removed by cutting the molded object 14, the molded object 15 having the shape of the screw thread cut into half at the surface containg the axis, is obtained. If two molded parts 15 are integrally stuck at their end surfaces 15a so that the phases of both screw threads are caused to coincide, and slitting etc., are formed on an axial end surface, a headless screw is completed. |
