What is Wire EDM and what are the advantages of using it?
Wire EDM is a method to cut conductive materials with a thin electrode that follows a programmed path. The electrode is a thin wire. Typical diameters range from .004"-.012" although smaller and larger diameters are available. The hardness of the work piece material has no detrimental effect on the cutting speed. There is no physical contact between the wire and the part being machined. Rather, the wire is charged to a voltage very rapidly. This wire is surrounded by deionized water. When the voltage reaches the correct level, a spark jumps the gap and melts a small portion of the work piece. The deionized water cools and flushes away the small particles from the gap.
The CNC machine can independently move four machines axes to generate taper cuts. A stamping die can be machined with 1/4 degree taper or a mold with one degree taper in some areas and two degrees in another with precision. Extrusion dies can be cut with the taper constantly changing. For example, a detailed shape on the top of the work piece can transition to a simple circle on the bottom.
Wire EDM can be accurate to +/-.0001". Virtually no burrs are generated. Since no cutting forces are present, wire EDM is ideal for delicate parts. No tooling is required so delivery times are short. Pieces up to 16" thick can be machined. Tools and parts are machined after heat treatment so dimensional accuracy is held and not affected by heat treat distortion.