As a rule, self-tapping screws have cross-shaped slit. It is simple to unscrew them from basis not always, especially, if they have been put on strong inhaling. As a result, we, without feeling sorry for forces and time, persistently we pick the self-tapping screw the screw-driver until we crush hat and to be hooked already just there will be nothing.
Instruction
1. For a start try to get nevertheless the self-tapping screw by means of the normal screw-driver – with assistance of file pierce groove under direct slit of the screw-driver and try to unscrew part. If it is impossible, - be not zealous too strongly, it will only aggravate situation. Use other methods.
2. If the case which is not absolutely started, then it is possible to try the following rather easy way – pick up the drill drill on diameter coinciding with self-tapping screw thickness. Also you drill it until the hat, does not separate from leg. It is necessary to do it very accurately as the swarf scattering at this moment very small and actively strives to get into eyes. Surely use special safety glasses! Many masters insistently advise to use the stud driver, noting its high functionality and efficiency even in the most hard cases.
3. After the part holding screw is liquidated, it will be necessary only to pull out leg from basis. It is possible to make it by means of combination pliers or simple flat-nose pliers.
4. If diameter of the self-tapping screw allows, it is possible to use other rather effective, but also very labor-consuming option. For this purpose drill on axis in screw the hole sufficient to insert into it tack or any to the friend thin and rigid metal part. After that accurately hammer it on half into the made opening. Bend and, besides accurately, begin to unscrew the self-tapping screw. In this case be ready to expenditure of considerable time – work jewelry.
5. In case screws have rusted, use WD 40 - it is the means allowing to soften rust and to remove surplus of moisture. Just fill in with it tenacious part and, whenever possible, try to hype up it to improve penetration of substance between the self-tapping screw and basis. Approximately in half an hour try to unscrew screw again. At the same time consider that the surface which was fat-free by WD 40 needs to be greased subsequently. Otherwise and according to destruction of part not to avoid corrosion. Therefore apply this means only to similar to the described problem of cases and also to moisture elimination from mechanical surfaces of parts and devices.