It is not recommended to use a wrench to unscrew a screw that has been severely corroded. This may screw the screw "head" of the prongs to the whole flat or screw the wrench bad. At this time, you can use the head of the wrench to knock the screw tail side, usually can be knocked loose in order to unscrew.

Method 2: Dripping

If the screw powder corrosion level is okay, you can try dripping oil, along the screw and parts of the combination of a small amount of motor oil or vegetable oil. This time with the use of wrenches or wire cutters, a gentle spin can be unscrewed. Note: If the corrosion is too serious, the general drop of oil is ineffective. And it will also affect the next removal.

Screws can not be screwed how

Method 3: burn

Some corrosion is serious, you can use fire.

①First screws and nuts with gas welding flame fully baked

② Immediately to the red-hot screws drop a few drops of oil

③ Because of the thermal expansion of the screws, the gap between the screws and nuts become larger. Slightly with a wrench against the bottom of the screw, and then drops of oil, drops of oil after the screw is cold contraction, increasing the gap between the screw and the combination of the screw, this time the screw will be very easy to unscrew. Note: If there is a plastic material next to the screw can not use this method. Moreover, the burned screws can not be used.

Screws can not be unscrewed how to do

Method 4: Induction heating - a very practical method

This method is very simple to operate, the scope of application: can be used for the removal, installation of a variety of metal parts of the work. Usage is very wide and there are few restrictions. It is very suitable in narrow space. It can be very precise localized heating, can perfectly avoid the workpiece outside the heated area, so that its original temperature remains unchanged. The heated part, due to thermal expansion, is loosened from the bond, this method is especially aimed at solving the problem of separation of nuts and bolts.