TRIANGULAR SECTIONAL SCREW AND MANUFACTURING METHOD THEREOF

摘要

PURPOSE: A triangular sectional screw is provided to economize the cost of a triangular sectional screw and to reduce the abrasion of a metal mold as well as to manufacture a triangular section part from the lower part of a head unit. CONSTITUTION: The triangular sectional screw is manufactured by the steps of:preparing a rod wire having a triangular section; fixing the prepared triangular sectional rod wire by introducing it to a circular hole of a metal mold unit; forming a head unit of a screw with the fixed rod wire in the circular hole; forming a screw thread on a screw unit having the triangular section by the rolling process.