| 摘要 |
<p>PROBLEM TO BE SOLVED: To firmly assemble a steel construction. SOLUTION: In the case of forming slide-restraining working surfaces in one side or both sides of the steel materials 2 for joining two steel materials 2 for steel construction, a roll-forming die 18C having an umbrella type working edge surface at the tip part of a tool 17 is arranged to press-weld a part of the working edge surface of the roll-forming die 18C to the steel material 2 as the roll-forming working surface portion.</p> |
