Screws and screws are a common type of fixing in daily life. Normally, they play a fastening role. Of course, we hope that they will be tighter, but this will also add some trouble to the subsequent maintenance technicians, especially When the screw is seriously rusted, it is difficult to unscrew it directly, and it is more likely to break or slip. At this time, people are like the eight immortals crossing the sea, and various methods appear, such as knocking, dripping, burning, flushing, etc. Welding, soaking, chopping, cutting, etc.
The first thing that ordinary people think of is "knocking". Most of the time, when they can't unscrew something, they just hammer twice, sometimes to vent their emotions. Without further ado, let's get to the point.
1. When knocking heavily corroded screws and they cannot be tightened, do not use excessive force to prevent the edges from slipping, breaking the screws or breaking the wrench. In this case, you can use a hammer or other instrument to gently tap the handle of the wrench, and use vibration to connect the rust to loosen the threads, and then you can twist.
2. For screws that are not seriously rusted, you can first try soaking them with dripping water. If they still cannot be unscrewed, drip a little engine oil or vegetable oil along the gaps between the screws and nuts. Use wire cutters and a wrench to unscrew them easily. (Using oil is ineffective for severely rusted screws and will affect disassembly) There is also a special chemical agent "drop screw" that acts on the contact surface between the screw and the tool to increase the friction of the contact to achieve increased friction. The effect of twisting force. After use, it can increase the friction force by 500 times, which is more than enough for ordinary dead screws. If it is used with complementary uses such as rust remover and lubricant, the effect will be more obvious.
3. Use a gas welding flame to fully grill the screws and nuts, and then drop engine oil on the red-hot screws or tighten them directly. This is because the screw shrinks when heated, increasing the gap. After the oil drips, the screw shrinks rapidly when cooled, further increasing the gap between the screw rod and the nut. The screw can be unscrewed after the oil flows in. (Note that screws with plastic parts nearby should be used with caution, and burned screws are not suitable for reuse)
4. If the flat opening or cross opening on the top of some screws is deformed and cannot be removed with a screwdriver, wrench, or wire cutter, the impact method can be used. First, use a hammer or a chopping knife to impact a V-shaped groove on the vertical surface of the top of the screw. Then adjust the angle of the chopping knife and strike in the direction of the thread. After loosening the screw for a while, you can use pliers to unscrew the screw.
5. Soaking: Soak the screws that need to be unscrewed in used engine oil for a period of time. The oil will penetrate into the screw teeth, so that they can be screwed. It just takes a long time to fit the screws that are not needed immediately.
6. Electromagnetic coil induction heating
A heating method that converts electrical energy into magnetic energy to induce eddy currents on the surface of the heated steel body. The above method of burning can be used anywhere, and is more suitable for narrow spaces. It can accurately partially heat, so that areas other than the heated object can still maintain the original temperature, reducing the impact on other parts. The heated object , it will shrink and loosen, making it easy to disassemble or install.
7. Welding This is mainly used to deal with the deformation of the nut, the screw slip angle, and the flat or cross deformation at the top of the screw. That is, put it on the nut and screw, and weld a good nut on the top to facilitate the operation of the tool.
The above are all relatively less destructive methods. The following is a destructive solution.
8. Chopping is mostly used to deal with nuts, and the nuts that cannot be twisted are chopped into pieces to separate them from the screw.
9. Use an electric drill to drill a hole in the screw head that cannot be screwed, and then use a counter-thread tapping tool to screw it. This is a common method to deal with the slip angle of the internal angle screw.
10. Nut breaker The nut breaker consists of a hydraulic cylinder, a cutter and a tool holder. It adopts a single-acting return hydraulic cylinder method to cut the nut into two halves at one time without damaging the screw and can continue to be used.
11. Cutting Use a small cutting machine to cut and break the nuts that cannot be tightened. Or use an oxygen cutter to burn the nut or screw into molten iron and blow it off.
