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