The tail of the self drilling screws is in the shape of drilling tail or sharp tail, which can be directly drilled, tapped and locked on the setting material and basic material, greatly saving the construction time without any auxiliary processing. Compared with ordinary screws, it has tough drawing force and high maintenance force, not easily loose after long time locked, safe to use. Especially in the construction, building, housing and all other places on the combination of work. Whether it is cost or credibility, self tapping self drilling screw is the best economic fastener.