Electrical discharge machining

This type of machining is based on electrical erosion phenomena accompanying electrical discharge between machine’s working electrode and machined item. That is why we call it electrical discharge machining ( EDM), which literally means “metal-removal process used to remove metal by means of electric spark erosion”. Therefore we can effectively apply it to all materials of electric conductivity above 10-2 S/m.

OElectrical discharge machining proves to be efficient especially in case of difficult-to-cut materials, such as cemented carbides or hardened work tool steel, which are slightly difficult to machine due to higher hardness. One of the advantages of EDM technology is the possibility of obtaining very complex shapes and high accuracy of performance. Electrical discharge machining is also effectively used for renovation of tools for plastic working, e.g. injection moulds.

EDM- electrical discharge machining is divided into two basic types: die sinking and electrical discharge wire cutting. First and foremost, they differ in working electrode being used.Sacher Company executes orders which require the application of both types of EDM.


In this type of EDM machining, a working electrode creates a hole in the material. In case of machines used by Sacher Company-Mitsubshi die-sinking EDM machines – it is a graphite or copper electrode. By using such technologically advanced tools, we are able to drill deep holes of very small diameter in various materials: cast iron, sinters, aluminum or various types of steel. Our die-sinking EDM machines guarantee high quality surface with surface roughness with of Ra ≤ 0,1 μm .Using a shaped electrodes allows us to produce high precision elements of complex shapes, such as casting or injection moulds.

Wire cut EDM

In case of machines used for second type of EDM machining, namely wire electrical discharge machining offered by Sacher Company, the role of a working electrode plays a wire with diameter from 0,1 to 0,35 mm. Wire cutting starts from already made  starting holes or from the edge of  machined object, whose height may be up to 220 mm in case of machines used by Sacher Company.

One of the main advantages of  this type of EDM technology, defined as WEDM- Wire Electrical Discharge Machining is elimination of cutting forces having a direct influence on machined object, which is impossible in case of  mechanical processing. It allows to manufacture very small elements, which could be damaged in case of abovementioned forces having an impact on machined object, for example when using a milling machine.

WEDM technology is at the same time the most precise metal cutting method, which provides precision higher than laser cutting, allowing to obtain surface quality with surface roughness  of  Ra ≤ 0,15 μm and with parallelism of  0,5 μm. This also applies to machining of materials characterized by very high hardness, that is why this technology is successfully used for the production of specialist tools for various branches of metallurgy , such as machining, plastic working or casting. By using cutting edge machines such as Mitsubishi wire-cut EDM machines, Sacher Company performs also order which require high level of precision and accuracy in case of complex shapes, which cannot be done using machining, like sharp external corners of an object.