TERMINAL PROTECTIVE STRUCTURE OF RESIN COATED METAL PIPE

摘要

PURPOSE:To certainly protect a male screw part from rust or damage by coating the male screw part formed to the terminal of a metal pipe with the same resin as other part and utilizing the release slit formed to the resin layer at the time of use to remove the resin layer applied to the male screw part. CONSTITUTION:A male screw is cut in the outer periphery of the terminal of a metal pipe 10 such as a steel pipe to form a male screw part 12 and a protective jig 30 having a flanged cylndrical shape and composed of a synthetic resin is fitted in the end part of the metal pipe 10. A resin layer 20 composed of a vinyl chloride resin is applied and formed to the outer periphery of the metal pipe 10 containing the protective jig 30 and the male screw part 12 and a plurality of release slits 40-44 are formed to the outer surface of the resin layer 20. The release layer 20 is raised up from the release slit 42 using an electric knife and peeled off along the circumferencial slits 40, 44. When the same operation is carried out on both sides of the release slit 42, the resin layer 20 is cut open left and right to be peeled from the metal pipe 10.