Broken bolt, this is always a very difficult situation. At first, it seems that it is almost impossible to twist such a bolt, because it is not even to capture it. However, experienced craftsmen who have been engaged in repair work for many years can suggest many ways that can help even in such seemingly hopeless situation.
So, from the very beginning, when the bolt is bad and I do not want to get out, you should not press too much on the tool, because the bolt is likely to break and the situation will become more and more complicated. What needs to be done is to pour it with liquid, which will dissolve rust, that is, VD40, as well as lubricants.
Of course, the liquids do not work right away and therefore the bolt must be left for about an hour in this state. From time to time you can tap it with a hammer so that the liquids penetrate better into the thread. And only after an hour you can try to carefully unscrew it.
It can not always help. If the bolt, no matter what, has broken, you will have to use various approaches that the masters developed with extensive experience.
For example, you can take a very thin and high -quality drill for metal and drill a line with its help under the screwdriver. If everything works out, the screwdriver is inserted into this groove, clamp it with a vice or a unitary key and try to unscrew it.
Another way is to weld or glue with very strong and aggressive glue to a broken bolt a bolt. Welding is not always available, but the glue is worth trying. If the rust by this time has already begun to dissolve, there is every chance to cope with the problem of such minimal efforts. The most important thing here is to be attentive and not allow the bolt itself to stick to the thread.
You can also drill a recess in the bolt, wind up the thread in this recess, and then tighten a little smaller bolt there. With this approach, the thread must be used in the opposite, from the available. That is, if the bolt has a standard thread, cut the left thread in it, otherwise this method will not work.
In rare cases, even such a method does not work. It remains to go to the most extreme measures. The bolt simply continues to be drunk (through) expanding the hole in it until its walls become completely thin. After that, the thin walls of the stubborn fasteners are broken and taken out in parts.