Electrical Discharge Machining

EDM (Electrical Discharge Machining) is a process that lends itself to precision machining of features when conventional machining is inappropriate.  For instance, if corner radii are not permissible, or need to be held to a tight tolerance, a “positive” shaped electrode can be machined and then “sunk” (burned) into the desired part.  Complex features, undercuts, small precise holes, square and blind holes, tight tolerance and fragile features are all examples of operations well suited for sinker EDM.

With EDM no pressure is applied to the material being machined as the features are burned to their shape rather than abraded.  Additionally, parts that have been heat treated, or must be heat treated prior to final machining, are excellent candidates for the EDM process.  Surface finish can be controlled during the EDM process allowing for variable appearances ranging from polished to textured surfaces.

Wire EDM provides for precision through-hole features to be machined into virtually any conductive material.  Applications include extremely small holes (diameters as small as 0.004”) or external (perimeter) features that are not suited for traditional machining.  Wire EDM also permits inclusion of tapered surfaces on features.  Variable angled undercuts and drafts are good examples, and tolerances within .0002” are possible. Surface finishes typically range between 4 to 64 micro inches for wire and sinker EDM; with the smoother finishes achieved using more precise process parameters.

Biomerics has 6 sinker EDM machines in our tool shops.