Bolt diagnostics

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When working in the field, crawler tractors, combine harvesters, straw returners and other farmland operating machinery may easily have the traction device bracket fixing bolts pulled off due to high traction resistance or lack of timely maintenance. Here's a way to remove a broken bolt. 　　1. Clean the dirt on the broken surface of the broken bolt, use a center bludgeon to drill a hole in the center of the section, then install a hand drill with a 6~8mm drill bit, and drill the hole in the center of the section. Note that this hole must be drilled through. After drilling through, remove the small drill bit and replace it with a drill bit with a diameter of 16mm, and continue to expand the bolt hole and drill through. 　　2. Select a welding rod with a diameter of less than 3.2m, and use small and medium current to perform overlay welding from the inside out in the drilled hole of the broken bolt. Use 1/2 of the entire length of the broken bolt as the starting point for overlay welding. When starting surfacing welding, do not strike the arc too long to avoid burning through the outer wall of the broken bolt. After surfacing to the upper end face of the broken bolt, continue surfacing welding to create a cylinder with a diameter of 14~16mm and a height of 8~10mm. 　　3. After the surfacing is completed, hammer the end face with a hand hammer to cause the broken bolt to vibrate along its axial direction. Due to the heat generated by the arc and subsequent cooling, coupled with the vibration at this time, the threads of the broken bolt and the machine body became loose. 　　4. Observe carefully after knocking. When you find that a small amount of rust ash escapes from the fracture, you can put the M18 nut on the surfacing column head and weld the two together. 　　5. After welding, the temperature can be cooled down slightly, and then while it is hot, use a torx wrench to twist the nut left and right (you can also tap the end face of the nut with a small hand hammer while twisting left and right). In this way, the broken bolt can be taken out. 　　6. After taking it out, use a suitable tap to process the threads in the rack hole to remove rust and other debris in the hole. This post was last edited by zzg5680 on 2008-12-13 16:59 ]