| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that, in the conventional pre-plated shape steel, since the opening part of the hole of gauging not used for bolt joining is not blocked by a bolt and a nut, red rust is easily generated from the inner circumferential face of the hole of gauging, and the retaining a beautiful appearance is difficult.SOLUTION: The pre-plated shape steel is composed in such a manner that each blockage body 3 made of punching scrap produced from punching process is inserted into each bolt hole 2, and impact is applied to each blockage body 3 to drop out each blockage body 3 from each bolt hole 2; thus each bolt hole 2 is opened. |
