초록 ▼

A drilling tapping screw includes a head engageable with rotary fastening tool, and a shank extending downward from the head and having a lower end having with a drilling tip, including a tapping and fastening thread defined from the end face thereof to the head. The head includes a pointed projecti

A drilling tapping screw includes a head engageable with rotary fastening tool, and a shank extending downward from the head and having a lower end having with a drilling tip, including a tapping and fastening thread defined from the end face thereof to the head. The head includes a pointed projection, an engaging portion engageable with the rotary fastening tool, and a collar. The pointed projection consists of a first tapered portion with a conical top end, a shaft with a fixed outer diameter, and a second tapered portion formed in the wake of the latter. Frame members made of steel are first firmly fastened by the screw, and joined to a wallboard, so that all the head portions except the collar stab the wallboard by striking with a hammer the site where the head is positioned. This temporarily locks the wallboard and prevent any warping of the site where the head is positioned in the wallboard.

대표청구항 ▼

[ What is claimed is:] [1.] A self-drilling and self-tapping screw comprising:a threaded shank;a self-drilling and self-tapping portion provided at a first end of said shank;a head provided at a second end of said shank and including a piercing portion; anda portion constructed and arranged to be en

[ What is claimed is:] [1.] A self-drilling and self-tapping screw comprising:a threaded shank;a self-drilling and self-tapping portion provided at a first end of said shank;a head provided at a second end of said shank and including a piercing portion; anda portion constructed and arranged to be engageable with a driving tool, wherein said portion constructed and arranged to be engageable with the driving tool comprises a grooved portion constructed and arranged to receive the driving tool.