| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a low torque tapping screw capable of reducing a fastening torque, raising a fastening speed, and efficiently preventing generation of cracks in articles during a screw fastening process. <P>SOLUTION: In the low torque tapping screw, each of thread ridges spirally formed in a shaft is constituted of three asymmetrical cutting faces, cutting edges are formed between optional adjacent two cutting faces of the three cutting faces, a plurality of saw teeth are opened in each of the cutting faces. Accordingly, due to a design where the cutting faces are asymmetrical and have the plurality of saw teeth, friction generated with the article is reduced, and a cutting efficiency can be raised, phenomenon in which a large amount of scrapes are accumulated is not generated, the fastening speed is raised by reducing the fastening torque, and the generation of cracks in the article is prevented when tapping and fastening by the thread ridges. <P>COPYRIGHT: (C)2013,JPO&INPIT |
