Do you CNC-machine custom parts?

Yes. We machine graphite and carbon-graphite parts from drawings or samples, with typical tolerances down to ±0.02 in depending on geometry and grade.

Do you carry high-purity isostatic graphite?

Yes. We stock industrial and high-purity isostatic graphite for EDM, precision components, molds, and vacuum or controlled-atmosphere applications.

Which graphite grade is best for EDM electrodes?

Fine detail and surface finish favor fine-grain, low-porosity isostatic grades. Faster stock removal uses coarser grades. We also offer impregnated blanks when lower wear or pore sealing is required.

When should I use a resin- or metal-impregnated blank?

Impregnation reduces open porosity, improves sealing, and can increase wear resistance. Resin is common for seals and EDM; metal impregnation adds conductivity and hardness for demanding mechanical uses.

Do you manufacture build-to-print?

Yes. From drawing or sample we make graphite/carbon parts: bushings, electrodes, crucibles, seals, molds, and special components, with dimensional control and traceability.

How is the graphite grade chosen for EDM?

On grain size and density. Finer-grain grades give better finish and hold small detail with less wear; medium-grain grades are more economical for roughing and large electrodes. Comparable values are in each grade datasheet.

Why graphite rather than copper?

Mainly manufacturing time: graphite machines far faster and allows thin walls and detail that are costly in copper. Copper keeps its place in specific very-fine-finish applications or small parts.

In which formats is it supplied?

As rods, plates, and blocks in shop sizes, or cut to electrode size. Stating the usable volume avoids paying for material that will become chips.

Does the same grade serve roughing and finishing?

It can be used, but it is not usual. Many shops keep a medium-grain grade for roughing and a fine grade for the finishing electrode, because wear and surface quality change appreciably.

Electrical applications

EDM electrodes

Essential components in the EDM process. Before manufacturing parts using EDM, the appropriate graphite grade must be selected.

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Electrical discharge machining electrode

Also known as: Graphite EDM electrodes · Electrical discharge machining electrodes · Graphite for sinker EDM · Graphite electrodes for mould making

[ Technical summary ]

In sinker EDM, the electrode reproduces the target shape in negative and is partly consumed during the process. Graphite dominates this application because it machines fast and in fine detail — allowing the electrode to be made in a fraction of the time copper requires — and because it withstands the discharge with comparatively low wear. The grade is chosen on grain size and density according to whether fast roughing or fine finishing is sought.

Graphite EDM electrodes need structural uniformity, machinability and dimensional stability during sinker EDM. ESGRAF recommends the material family by finish, wear rate and geometry complexity.

For grade selection and specifications, see EDM graphite. For finished electrodes to print, graphite machining. Industry context: EDM industry.

[ Problem it solves ]

Produce cavities and details that cannot be cut by conventional machining, with an electrode that is fast to make and holds its shape during erosion.

Operating conditions

Sinker EDM
Electrode machining

When it is suitable

The geometry cannot be produced by conventional cutting
The electrode must be made quickly and in fine detail
The cavity requires sharp edges or deep walls
Hardened steels or hard-to-machine materials are being eroded

When it may not be suitable

The process is wire EDM rather than sinker EDM
The shop cannot control the dust from machining the electrode
The target finish requires a finer grade than the shop has available

Process challenges

Uneven electrode wear
Poor surface finish
Incorrect grade selection

Advantages

Excellent machinability
Good erosion performance
Grades for fine finish or roughing

Limitations

Wear from arcing or electrical erosion
Conductivity and density must be calibrated to the process
Some grades are not suitable for high purity

[ Critical selection variables ]

These variables define the grade and the geometry. Actual values are confirmed against the grade datasheet.

Geometry to erode and fine detailDecisive
Roughing or finishing regimeDecisive
Surface finish required on the partDecisive
Current densityRelevant
Geometry and tolerancesRelevant
Required purity and allowable contaminationRelevant

[ Required material properties ]

Properties that guide selection. Numerical values come from each grade's datasheet.

Critical properties

Electrical resistivity
Machinability
Flexural strength
Grain size

Secondary properties

Bulk density
Hardness
Dimensional stability

[ Related ]

[ Frequently asked questions ]

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Technical content reviewed by ESGRAF — Last reviewed: September 8, 2026

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