Screw and method of its manufacture

    公开(公告)号:US10580593B2

    公开(公告)日:2020-03-03

    申请号:US15119997

    申请日:2015-03-16

    摘要: A screw includes a barrel-shaped central pin is surrounded by a cylindrical bore having a conical bottom The cylindrical insert is seated in the cylindrical bore. The top surface of the central pin is lowered below the top surface of the head. The walls of the pin (4) are convex towards the insert. Manufacturing the screw includes producing the threaded part with the head with the cylindrical recess with the cone-shaped bottom. The cylindrical insert terminates at one end with a bevel with an inclination angle of α=10-30°. The insert is introduced into the cylindrical recess. The upper part of the insert protruding from head of the screw is pre-shaped. The pin is upset using an appropriate tool and simultaneously the top surface of the pin is lowered below the top surface of the head.