At modern enterprises, when performing locksmith work, the breakdown of taps and other tools is one of the reasons for the lack of parts. It occurs, mainly, as a result of errors in work methods and poor selection of taps. Known methods of mechanical extraction of a broken tool are not universal and do not guarantee high-quality extraction. In this regard, the methods of electroerosion processing are of some practical interest, as they are more universal and reliable. EDM methods that can be used today to remove the remains of a broken tool include EDM, EDM, and EDM. It is shown that the most productive method is the method of dimensional processing of metals using an electric arc (ARC). Its performance is 8-10 times higher than the performance of electric pulse processing. That is why the well-known method of removing a broken tool is carried out with the help of an EDM head, which implements the ROD method. The head is created on the basis of a desktop drilling machine. Round electrodes- tools made of a copper tube are used to stitch the hole in the broken part of the tool. However, since the height of the broken part of the tool can reach 50 mm, the volume of metal to be destroyed is large, and therefore the time spent on piercing the hole remains quite significant. In addition, the large linear wear of the copper electrode-tool significantly affects the cost of processing, and the use of low-wear graphite electrodes-tools for ROD of the hole in the broken part of the tool is complicated by the problem of their manufacture: small diameter, long length. The purpose of the study is to improve the operational characteristics of the method of extracting a broken tool with the use of electroerosion processing due to the application of another extraction principle. In the new method of removing a broken tool using electroerosion treatment, the process is proposed to be carried out in two stages. At the first stage, with the help of an EDM head for ROD, a shallow recess of a non-round (triangular, quadrilateral or hexagonal) section is formed for the metal cutting machine. The process is carried out with a short graphite electrode-tool. On the second, an L-shaped key is inserted into the recess and the broken part is unscrewed by rotating it. It is shown that its use improves operational characteristics and allows to reduce processing time by 4-5 times, and to reduce the cost of tool electrodes by 2-3 times.

EDM head, dimensional arc machining, bench drilling machine, machining performance, tool electrodes