| 摘要 |
A directly connected screw structure is provided to fit a male thread of a screw body into a hole formed by a drill part, thereby improving coupling force of the screw. A directly connected screw structure includes a head(1), a screw body(2), and a drill part(3). The drill part is formed at a tip of the screw body. A male thread(21) is formed at an outer periphery of the screw body. A blade part(31) is formed at a lower end of the screw body, with two blades(32) symmetrical with respect to the centerline of the drill part. A cutting edge(33) is formed at a tip part of the blade part. The blade part is formed at the drill part at an angle of 7.5 to 10 degrees with respect to the outer periphery of the screw body. The cutting edge is formed at the angle of 39 degrees with respect to a horizontal line.
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