Common sense of screw application

1. First remove the sludge on the broken surface of the broken screw and use the center gun to kill the center of the section, then use the electric drill to install a drill bit with a diameter of 6-8 mm to drill the hole at the center of the section, and pay attention to the hole must be drilled thoroughly. After the hole is drilled through, remove the small drill bit, replace it with a drill bit with a diameter of 16 mm, and continue to expand and drill through the hole of the broken bolt.
2. Take the welding rod with diameter less than 3.2 mm and use medium and small current to weld the broken bolt from inside to outside in the hole of the broken bolt. Take half of the whole length of the broken bolt at the beginning of surfacing welding. When starting surfacing welding, the arc striking should not be too long to avoid burning through the outer wall of the broken bolt. After surfacing to the upper end of the broken bolt, continue to weld a cylinder with diameter of 14-16 mm and height of 8-10 mm.
3. After surfacing, hammer the end face with a hammer to make the broken bolt vibrate along its axial direction. Because of the heat generated by the previous arc and the subsequent cooling and the vibration at this time, the thread between the broken bolt and the body will become loose.
4. Observe carefully. When a small amount of rust is found to leak out from the fracture after striking, take the M18 nut and cover it on the overlaying stud and weld the two.
5. After welding, use a ring wrench to put it on the nut and twist it back and forth when it is hot. You can also use a small hammer to knock the end face of the nut while twisting it back and forth to take out the broken bolt.
6. After taking out the broken bolt, use a suitable tap to process the thread in the frame once to remove the rust and other sundries in the hole.