In the process of repairing and construction there are often situations when the fastening element breaks off and its piece stays in the material. This can occur due to some defects of fasteners, corrosion, high temperature or disruption of the bolt head when tightening. Extractors are used to take out fasteners without damaging the thread in the whole. The design of this tool resembles a steel rod with a left carving on the end. There are different sizes and types of extractors. Wedge extractor is a cone shaped device, which is clogged into a pre-drilled part of a broken bolt. Then it is turned out with a key. Rod extractor is hammered into the broken part and turned out with a wrench. The most common and effective extractor is a spiral one. The tool is screwed into the bolt hole and easily extracted.