Electrical Discharge Machining

Sinker EDM, also called ram EDM, cavity type EDM or volume EDM, consists of an electrode and workpiece submerged in an insulating liquid such as, more typically, oil or, less frequently, other dielectric fluids. The electrode and workpiece are connected to a suitable power supply. The power supply generates an electrical potential between the two parts. As the electrode approaches the workpiece, dielectric breakdown occurs in the fluid, forming plasma channel, and a small spark jumps.

These sparks usually strike one at a time, because it is very unlikely that different locations in the inter-electrode space have the identical local electrical characteristics which would enable a spark to occur simultaneously in all such locations. These sparks happen in huge numbers at seemingly random locations between the electrode and the workpiece. As the base metal is eroded, and the spark gap subsequently increased, the electrode is lowered automatically by the machine so that the process can continue uninterrupted.

-  cuts any electrically conductive material (aluminum, carbide, Inconel, titanium, stainless steel, etc...)

-  submerged cutting for thermal stability

-  Incredible accuracy and able to meet tight tolerances up to +/- .0001

- Boast the ability to burn complex shapes of varying sizes.

-  stress free cutting with no burrs

-  excellent finishes (up to 10 - 15  Ra possible)

Wire EDM (electric discharge machining) is a method of high precision machining for cutting almost any electrically conductive material.  A constant flow of electrically charged wire (.004" -.012" diameter) held between upper and lower mechanical guides create one electrode, while the material being cut forms the second electrode.  An electrical discharge between the wire and the work piece create precisely controlled sparks that erode away material with extreme accuracy.  The wire and work piece are both submerged in nonconductive, deionized water, which cools and flushes away eroded metal particles.  The temperature of the fluid is regulated to match the atmospheric conditions in the shop to eliminate thermal expansion that is common with traditional machining practices. This eliminates thermal movement and provides a stable environment for the close tolerances that EDM is capable of.  Since the wire never makes physical contact with the work piece, no cutting forces are involved.  This makes it possible to manufacture delicate pieces, or parts which may be challenging to hold due to their shape.  This also contributes to the fact that the hardness of the material being cut has little effect on the EDM process.  In fact, difficult to machine alloys such as Inconel and carbide are only a few of the materials that can be easily machined using wire EDM.

-  cuts any electrically conductive material (aluminum, carbide, Inconel, titanium, stainless steel, etc...)

-  submerged cutting for thermal stability

-  cuts tapers, angles, and contours with up to +/- .0001" accuracy

-  stress free cutting with no burrs

-  excellent finishes (up to 10 - 15  Ra possible)