I have liquid wrench or rust remover, WD-40 on hand, which can be sprayed and soaked for half a day. Combined with the following methods, I can solve the problem in the following aspects:
1. Shock: for rusty screws and nuts, never use a spanner to screw them hard, so as to prevent slipping the hexagon angle of the screw and nut, breaking the screw or damaging the spanner. At this time, the handle of the wrench can be gently shaken with a hammer. Generally, the rusted screws can be shaken off.
2. Knock: knock the rusty stainless steel nut with the edge of square hammer, it is easy to make the nut loose. For example, the fixed bolts and nuts on both ends of the pedal of a bicycle can be knocked on the nut according to the thickness and metal structure of the pedal. The non-standard nut of cast iron can be forced slightly, and the plastic part should be knocked gently. If it doesn't work, use a hammer to knock the nut in a circle in the direction, and the nut can be easily removed.
3. Burn: some screws are seriously rusted, but the above method is still ineffective, so "fire attack" can be used. Use gas welding oxidation flame to bake the non-standard screw and nut, and then drop a little oil on the red screw. The purpose of heating screws is to make them expand when heated. The purpose of oil dripping is to make the screw shrink rapidly when it is cold, increase the gap between the screw rod and the stainless steel nut, and the nut can be unscrewed after the oil flows in. However, if there are plastic parts nearby, use this method with caution.
4. Punching: the top of stainless steel screw of some devices is corroded and out of shape, so it can not be unloaded with spanner or steel wire pliers. The impact method can be used. First, impact a V-shaped groove vertically on the top of the screw with a hammer and a turbine driver. Then, adjust the angle of the punch cone and impact along the direction of the screw. After loosening, the screw can be screwed out with steel wire pliers“ This method can also be used in combination with steel wire pliers to screw out the screw when the "one" or "ten" screw slide.
5. Soldering: it is common to break the screw when disassembling the device. For the broken screw, generally do not use electric drill, because the slightest carelessness will drill bad wire hole. The better way is to weld a long iron block on the broken wire by electric welding. The cross section of the iron block is determined by the diameter of the stainless steel screw.
