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How to choose graphite?

There are numerous opinions on the choice of graphite for a particular job. We believe that objectively there are five basic factors for choosing the material of the future electrode. These factors actually determine whether and to what extent a particular project will be laborious and successful.


Five key factors to choose from

1. material removal (eroding rate) varies considerably according to the graphite class. The right choice of graphite grade for an electrode of a given shape allows you to maximize the rate of material removal with minimal electrode wear.


2. Electrode wear cannot be completely prevented. The choice of the right material for the electrode and the optimal setting of the machining parameters significantly minimizes wear. This makes it possible to reduce the number of electrodes required for the efficient construction of cavities and thus the cost of their production.


3. fine surface treatment is obtained by a combination of suitable electrode material, rinsing conditions and correct setting of the generator parameters. To achieve the best surface of the cavity, it is necessary to work with graphite containing ultrafine or angstrom particles and with graphites with high strength.


4. The hardness of graphite is an important factor for its machinability. Good machinability guarantees precise shape perfection of the electrode and affects production costs. At the same time, the graphite must be strong enough to withstand possible damage during handling and wear during the electrospark process itself. Strength and small particle size are important to achieve minimum radii and small tolerances.


5. The price of graphite for the acquisition of an electrode tends to be negligible in relation to the total cost of mold production. This fact is often overlooked. When calculating costs, the time required for its production, the time of the electroerosive process, the wear of the electrode have a much greater weight and machine operating costs. Therefore, it pays to know the properties of graphite and the performance characteristics of the electrode material and their effect on the workpiece during machining.


If you have any doubts about choosing the right grade of graphite, please contact us at any time.
We respond immediately because we know that production times are set and time costs money.

Is there universal graphite?

An electrode from one class of graphite, which is suitable for a certain job, gives completely different results than an electrode from another class at the same setting parameters.The differences are in, among other things, machinability, electrode quality, removal rate, surface quality and electrode wear. In other words, with different graphite, the same work may be done, but the quality of the cavity and the cost of making it will vary significantly.

What is the use of knowledge of graphite properties?

Forms are becoming more complex, pressure on prices greater and deadlines shorter and shorter. Knowledge of the properties of graphites and their structure is a condition for the correct selection of graphite for the production of the electrode as an original tool for machining. The electrode material co-creates the difference between profit and loss, success and failure.


The graphite, the better the electrode. As the electrode is, so will the cavity. The cavity is a mirror of the electrode.

Spark gap size

The spark gap (GAP) together with the graphite material has a decisive influence on the efficiency of the EDM process. Co-decides on the rate of eroding, production times and costs, quality of work. Improperly chosen spark gap is also often the cause of problems that occur when working with graphite. We know that the GAP change has accelerated the fabrication of the cavity by tens of percent in some operations. Determining the size of the spark gap requires experience. We are also available here.

Can graphites also be cut?

Yes, some grades of graphite can be cut on a wire board to create an electrode with interesting and extraordinary details. In practice, the most commonly used graphites are EDM-3, EDM-C3, EDM-C200 and EDM-1. Experienced staff should also be able to handle other classes.

How to dispose of graphite waste?

Tool shops solve the disposal of graphite dust and cuttings, which arise during the production of electrodes, in various ways.We cater to those tool shops that guarantee that the waste contains exclusively POCO graphite materials. In that case, we will buy it.


Despite all the precautions and principles of graphite waste sorting, used electrodes and impurities may also appear in it. In this case, too, we are able to provide this service.


As part of the protection of work and the environment and health, the production of electrodes and the associated occupational hygiene is in the permanent interest of TEDOK / POCO companies. For example, by providing consultations on how to reduce the number of electrodes required for the production of mold cavities and thus, among other things, to reduce the amount of graphite waste.

This service is available only for customers based in the Czech Republic.

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