Selbstschneidende Schraube

摘要

The invention relates to an improvement of a tapping screw which is fastened to a subject while forming a female screw in a prepared hole of the subject by a thread portion formed in a shaft portion. The tapping screw is provided with three features that an angle of a thread ridge is approximately 30 degree, a notch (30) is partly formed in a top portion of the thread portion in a predetermined range of an entire length of the shaft portion, and a joint portion (140) for connecting the top portion (130) and a bottom portion (131) of the thread portion (30) is formed in a circular arc shape in an area having a smaller diameter than a diameter of the prepared hole of the subject, in a cross section including a shaft center of the tapping screw. Accordingly, it is possible to make a screwing torque into the subj ect small. Further, since it is possible to plastically deform the subject without overburden, the female screw in the peripheral surface of the prepared hole of the subject is not easily broken.