In another experiment, the drilling screw 11, whose smaller diameter parallel thread parts {HEAD ~ outer diameter} was increased to be 2.1 mm, was fastened with {TAIL ~ the impact type air driven screw fastener} 
In another experiment , the drilling screw 11 , whose smaller diameter parallel thread parts { HEAD ~ outer diameter } was increased to be 2.1 mm , was fastened with { TAIL ~ the impact type air driven screw fastener }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL