When the drilling screw 11 is hammered into the gypsum board and {TAIL ~ the C type steel plate structural material} with the impact type air driven screw fastener, the smaller diameter parallel thread part 15 is inserted through {HEAD ~ the steel plate} 
When the drilling screw 11 is hammered into the gypsum board and { TAIL ~ the C type steel plate structural material } with the impact type air driven screw fastener , the smaller diameter parallel thread part 15 is inserted through { HEAD ~ the steel plate }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD