| 摘要 |
The present invention is in particular to a first threaded section and a second threaded section both consisted of a plurality of threads are spirally disposed on the shank and connecting each other. Moreover, said first threaded section is a continuous threaded section, and said second threaded section is a non-continuous threaded section. While in operation, with said first threaded screwing, the user can save more labor in screwing the present invention. Further accompanying with said non-continuous second threaded section, the debris cut from the object can be accumulated inside said second threaded section and connected together. Therefore, the present invention will be well fastened into the object after screwing. |
