1. When using micro screws, be sure to remove the sludge on the surface of the broken end of the screw, and then pay attention to use an electric drill to install a suitable size drill bit to drill the hole in the center of the screw section. The originally larger drill bit continues to expand and drill through the hole of the broken bolt;

 

2. Pay attention to take out the electrode with smaller diameter and use the center current to carry out the surfacing work from the inside to the outside of the drill hole of the miniature screw, and the part where the surfacing starts should be cut off by half of the overall length of the bolt;

 

3. After the surfacing operation is completed, a hand hammer should be used to hammer the end face of the miniature screw, and the broken head bolt should vibrate along its axis. The nut is placed on the surfacing column head and the two are welded together.