| 摘要 |
Disclosed is a screw plug (10) for a liquid conduit, particularly an oil pipe or an oil container, comprising a cylindrical shaft (36) that is placed on a top plate (12) and is provided with an external thread (22). A pocket hole (28) having a polygonal cross section is centrally arranged on the top plate as a receiving member for a tool. The shaft (36) is embodied as a tubular butt (14) that is provided with the external thread (22). A pocket hole (18) which is arranged coaxial to the pocket hole (28) of the top plate (12) extends from the face (16) of the shaft. In order to produce said screw plug (10), a blank comprising the cylindrical tubular butt (36) that is connected to the top plate (12) in a molded-on manner is made, the inner diameter and outer diameter of said tubular butt (36) being smaller than the final corresponding diameters (e, f) of the screw plug (10). The tubular butt (36) of the blank is then enlarged by applying pressure to the inner wall surface of the pocket hole thereof. Also disclosed is a tool for carrying out the inventive method, in which one end of a pressure die is fixed as a mandrel-type tool while a supporting or holding head which is disposed so as to be movable relative thereto and encompasses a seat for a blank is associated with the free end thereof. |
