| 摘要 |
PROBLEM TO BE SOLVED: To provide a drive fastener having excellent fastening strength. SOLUTION: This fastener 1 is provided with a shaft 2 and a head part 3 provided at one end (base end) of the shaft 2, and the shaft 2 is formed with a straight boring part 4 and a group of annular projections 7. The peripheral edge of a tip of the boring part 4 is formed into an acute cutting edge 6 by forming the tip surface of the boring part 4 with a recess. An appropriate range from the boring part 4 to a position close to the head part 3 is formed into a taper part 9. When fastening steel plates 10 and 11 to each other, a prepared hole 12 is bored in the steel plates 10 and 11 by the boring part 4, and the steel plates 10 and 11 are formed with barring parts 10a and 11a hardly having a rugged part. With this structure, the barring part 10a is securely hooked on the annular projections 7 to secure the high fastening strength.
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