Cross sink self-drill screw

The difference between the self-drilling self-tapping screw and the ordinary self-tapping screw is connected through the two processes of drilling (drilling thread bottom hole) and tapping (including tightening connection); when the self-drilling self-tapping screw is connected, the drilling and tapping screw are combined once. It first uses the drill bit in front of the screw, and then uses screws (including fastening connections) to save construction time and improve construction efficiency.