| 摘要 |
PROBLEM TO BE SOLVED: To provide a self-tapping screw for eliminating the product of long and large shaping or cutting scraps by reducing the inclination of a screw to be screwed. SOLUTION: The screw has a leg 3 to be screwed while forming a female screw. The leg 3 consists of a fastening part 12 and a fastening guide part 13, and the fastening part 12 is formed with its equal thread height H from a valley part 11 of the leg 3. The fastening guide part 13 has a thread ridge line gradually lower as reaching the front end of the leg and a thread peak angleαlarger, and the base of a thread 10 has a greater width L as reaching the front end of the leg 3. This allows easy work for screwing into a prepared hole at the beginning of the screwing and actualizes the smooth flow of a raw material to the thread peak during rolling work for the thread. COPYRIGHT: (C)2009,JPO&INPIT
|
