| 摘要 |
The present invention pertains to a screw (3) for use in nonmetal objects comprising a plurality of cut-aiding portions (311) formed by the longer (312) and shorter (313) cutting surfaces inclined toward an opposite direction. Further, a cutting edge (314) formed by the junction of any two adjacent cutting surfaces (312,313) presents in a fastening direction of the screw. Thus, the cutting edge assists the threads (33) to thoroughly severe and to shatter the wood fibers and debris of the objects, which can also be accommodated into the cut-aiding portions. Also, the ridge (317) of the longer cutting surface (312) aids in cutting fibers and further guides the debris out. In this manner, the present invention facilitates to enhance cutting capability with less screwing resistance, prevent the destruction of the object and increase the screwing speed. |
