| 摘要 |
PURPOSE: To increase a removing force to a value which is several times as large as an inserting force by providing a rigid stop means which laterally extends from a shank, between at least one of wing members and a free end part of the shank. CONSTITUTION: When a fastener 10 is pushed in an opening 22, wing members 18 are continuously flexed. Further, when the fastener 10 is to be pulled out from the opening 22, a set of wing members 18 adjacent to a workpiece 23, is engaged with the lower surface of the workpiece 23, and accordingly, the wing member 18 is flexed toward the free end part 16 of the rigid shank 14. The lower surfaces of the wing members 18 are engaged with a stop member 26 directly therebelow, and accordingly, the wing members 18 are inhibited from being further flexed. Accordingly, the fastener 10 cannot be pulled out unless the wind members 18 are sheared at their thickest and high strength positions. If the thickness of the wing member 18 is changed, the force for pulling out the fastener 10 can be changed.
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