The drilling screw 11 comprising {HEAD ~ the parallel thread part} 13 and {TAIL ~ the smaller diameter parallel thread part} 15 which are connected through the taper thread part 14 
The drilling screw 11 comprising { HEAD ~ the parallel thread part } 13 and { TAIL ~ the smaller diameter parallel thread part } 15 which are connected through the taper thread part 14
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH