Quite often, when using such fasteners as a bolt, situations arise when the head of the product breaks off and the hardware remains inside. In this case, it becomes necessary to remove this residue without damaging the threads, so that the hole could be further exploited. Given this, the topic of how to unscrew a broken bolt is very popular and requires more detailed consideration.

How to unscrew a broken bolt without damaging the thread in the hole

Kinds of kinks

Typically, such fasteners breaks at the end of the thread, although there may be exceptions. As a result, the hardware itself can be recessed into the hole, protrude above the surface or even with it. Based on this, to decide how to unscrew the broken bolt, you need, paying attention to this moment.

Surface breakage

This type of breakage refers to the option when part of the hardware protrudes above the surface. We can assume that this problem is solved most easily, without using radical measures. However, before making any twisting of a broken bolt, it is worth treating the place with kerosene to remove carbon and weaken the contact of surfaces.

  • If the protrusion is quite large, then the easiest way to use tools like pliers, tongs or clamps, with which you can grip the part and twist it along the thread.
  • Some experts, answering the question what to do if a bolt that fits very tightly in a hole broke, recommend using a welding machine. With it, you can weld a lever to the hardware, which as a result will provide a large shoulder for the rotational motion.
  • You can also use a drill with a diameter slightly smaller than the bolt itself. A hole is drilled through the central axis of the bolt to the full depth. After that, the remnants of fasteners are removed using a hook, trying to unscrew the thread from the bottom.

Breakage flush

It is believed that this failure is the most difficult, because sometimes it is very difficult to determine the diameter of the hole, especially if the fastener was cut. Therefore, in order to determine how to drill a broken bolt of this type, it is first necessary to clean the surface, determining the gaps.

Quite often the place of a cliff has very uneven forms, which, with such an arrangement, are very difficult to straighten out. Drilling in this state the product will not work. That is why at first they use a core, which is used to prepare a place in the center for working with a drill.

Further actions describing how to drill out a broken bolt are described in the paragraph about the surface break. After making the hole, the remnants of the thread are simply removed with a hook.

Break below surface

Such damage is quite complicated, especially if the part itself is made of soft metal. Therefore, it is necessary to solve the problem of how to unscrew the broken bolt and at the same time not damage the threads in the hole.

First of all, with the use of core mark the center of the hardware. It is best to use a thin tool made of durable metal, so as not to accidentally damage the part.

The next step is to purchase a tap with reverse thread. Its diameter should be smaller than the bolt itself.

After that, in the hardware, they drill a hole for the tap, but they do not deepen it much. Next, it is enough to install a tool for threading and turn it along the way, which will lead to twisting. If this does not happen, then the tool is used as a normal bolt, but you should not exert too much effort not to break it.


The most correct answer to the question of how to unscrew a broken bolt is considered to be the one in which they propose to use a tool specially created for this purpose. It is called an extractor and is sold as a set of products of different diameters. Outwardly, it resembles a tap, but without longitudinal slits and with a tapered notch for cutting.

To use the extractor, it is enough to drill a hole in the center with a diameter that allows the tool to go for several turns. Then begin to turn it all the way, and then to complete twisting.

There are several options for removing broken bolts from the hole that can be used for certain types of damage. However, it is best to pre-purchase a set of extractors that can be considered the best tools for such tasks.