Soak in kerosene for 20-30 minutes. Use a hammer to tap around the nut to loosen the rust layer, and then unscrew it. If it still cannot be removed, use a blowtorch to heat the nut. When the nut is heated and expands, and the threaded standard part is slightly heated, the nut can be quickly unscrewed.

If it is a threaded slider, an enlarged hole can be drilled at the threaded hole, and the thread can be modified. Then, a stepped bolt can be prepared with one end enlarged and the other end maintaining the original diameter. Expand the original screw hole and process an internal and external threaded nut. The outer diameter matches the enlarged screw hole, the inner screw hole is the same as the original diameter, and the outer thread is coated with 502 glue. When the diameter of the head screw is larger and relatively loose, it is then screwed into the enlarged screw hole.

You can use a hand hammer and a flat chisel to slowly remove the thread in the opposite direction of the thread. If the broken end is higher than the end face, file it into a square shape and screw it out, or weld a nut at the broken end and screw it out.

If the broken end is slightly higher than the end face or there is no outcrop, drill a hole at the broken end, and then wedge it into a multi edged quenched steel shovel and rotate it out; Use reverse screws to unscrew the broken end with reverse threads. When it is allowed to expand the screw hole, the broken screw can be drilled out with a drill bit and the thread can be expanded again.

To prevent deformation of standard components due to uneven stress, the screw groups should be symmetrically and diagonally removed. When disassembling, first loosen screws 1 to 2, and then disassemble them one by one. For square or circular parts, disassemble them symmetrically along the diagonal or center.

The elongated parts can be gradually loosened and disassembled in a symmetrical diagonal order from both sides to the middle or from the middle to both sides. First, loosen and remove the screws in the difficult area. When disassembling the cantilever multi screw standard connector, start from the bottom and loosen it in a symmetrical position. One or two screws on the upper part should be removed, otherwise it may cause accidents or deformation and damage to the parts.