| 摘要 |
PURPOSE:To elevate the productivity of a fiber-reinforced plastic bolt with an easier thread rolling by bringing a heat medium with a specific temperature into contact with a cylindrical material in the thread rolling of the material with the surface layer made of a reinforcing fiber dispersed thermoplastic resin. CONSTITUTION:When a thread is formed with thread rolling dies on the surface layer of a cylindrical material in which at least the surface layer is made of a thermoplastic resin dispersed with reinforcing fiber, a heat medium above the transition point and below melting point of the thermoplastic resin in thermal medium (e.g. silicone oil) is brought into contact with the cylindrical material and then, the material undergoes a thread rolling with a thread rolling dies (preferably, controlled to the temperature below the transition point of the thermoplastic resin) by heating the surface layer thereof. |
