| 摘要 |
PROBLEM TO BE SOLVED: To provide inexpensive section steel for a beam member, in which a through-hole can be reinforced without using a reinforcing member or increasing the thickness of a web, and a method for forming a through-hole.SOLUTION: The section steel for a beam member is provided that includes upper and lower flanges 12 and 14, and a web 16 which connects the upper and lower flanges 12 and 14 together and in which a through-hole 18 is opened. The through-hole 18 is formed in such a way that an inside diameter of an opening provided in the web 16 is enlarged by plastic working for cylindrically and plastically deforming the periphery of the opening and a flange 20 is formed to protrude in one direction orthogonal to the web 16.SELECTED DRAWING: Figure 1 |
