Do not use a wrench to hard-twist the severely corroded screws, so as not to slip the angle, break the screws or break the wrench. At this time, you can gently tap the handle of the wrench with a hammer, and the corroded screw will often loosen to loosen it.

2. Didi.

You can drop a little oil or vegetable oil along the gap between the screw and the nut, and you can easily unscrew it with wire cutters and wrenches.

Step 3 burn. Some screws are seriously corroded and can be attacked by fire.

Step: (1) fully barbecue the screws and nuts with gas welding flame; (2) Drop engine oil or sewing machine oil on the red-hot screw. (3) When the screw expands when heated, it will squeeze the rust between the screw and the nut, which will increase the gap. After dripping oil, the screw will shrink quickly when it is cold, further increasing the gap between the screw and the nut. After the oil flows in, you can unscrew the screw. Note that this method should be used with caution for screws with plastic parts nearby, and burnt screws should not be used again.

4. rush Some screws are deformed at the top, which can't be removed with screwdriver, wrench and wire pliers. Impact method can be used.

Steps: (1) First, impact a V-shaped groove on the vertical plane at the top of the screw with a hammer; (2) Then adjust the angle of the slotted screwdriver and impact along the direction in which the thread is screwed out; (3) After loosening the screw, screw it out with wire cutters.

5. welding.

After the screw is broken, it is best not to drill through it with an electric drill, otherwise the casing will be damaged due to the sliding of the drill bit, or the threaded hole will be enlarged and need to be tapped again. A better way is to (1) weld an iron bar or flat iron on the broken screw by electric welding, and the cross section of the flat iron is determined by the diameter of the screw. (2) After the flat iron is welded firmly, quickly drip engine oil into the weld to make the engine oil soak the nut. (3) After cooling, tap the other end of the flat iron back and forth along the horizontal direction with a small hammer. After the screw is loosened, turn the flat iron to screw out the broken nail.

6, bubble. None of the above methods can be used for plastic screws or screws fastening plastic parts. At this point, the screw can be easily removed by soaking it in water or engine oil for several hours.