Sinker EDM Machining Process

The sinker EDM machining (Electrical Discharge Machining) process uses an electrically charged electrode that is configured to a specific geometry to burn the geometry of the electrode into a metal component. The sinker EDM process is commonly used in the production of dies and molds.

How Sinker EDM works

Two metal parts submerged in an insulating liquid are connected to a source of current which is switched on and off automatically depending on the parameters set on the controller. When the current is switched on, an electric tension is created between the two metal parts.

Sinker EDM Machining: Sharp SED Series Z-Axis NC

If the two parts are brought together to within a fraction of an inch, the electrical tension is discharged and a spark jumps across. Where it strikes, the metal is heated up so much that it melts.

Innumerable such sparks spray, one after the other (never simultaneously) and gradually shape the desired form in the piece of metal, according to the shape of the electrode. Several hundred thousand sparks must fly per second before erosion takes place.

Die-sinking EDM Machining

In the case of die-sinking EDM, the required shape is formed negatively in the metal with a three-dimensional electrode. By superimposed movements in the main axes x, y, c, z, the most varied shapes, indentations and cavities are created, such as cannot in part be achieved by any other machining system. Sinker EDM Example

For example, a helicoid cavity or a rectangular hole in one single steel block or the machining of an extremely thin, hardened steel sheet that may not be subjected to any mechanical pressure.

For More Information

For more information on the Sinker EDM process, contact the people at:
    IDS Machining (

If you have questions about EDM Machining contact us.

IDS Machining has over 25 years of industry machining experience in the following areas:

  • EDM Machining
  • Wire EDM
  • Sinker EDM
  • Plastic Injection Molds
  • Lost Foam Molds
  • Vacuum Form Molds
  • Smashing Dies
  • Forming Dies
  • Small Lot Production Runs
  • Lost Wax Molds
  • Silicone Injection Molds
  • Tool and Die
  • Prototypes
  • Fixtures
  • Lathe Work

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