EDM drilling uses the same mechanism as traditional electric discharge machining, but usually uses a tube-shaped electrode to cut a hole through the material. The properties of the EDM drilling process allow users to create holes with properties unlike those made with traditional rotating drills. The holes need not be circular, and can be much more irregularly shaped. The use of this process can provide finished goods with very tight tolerances and high repeatablity, with lowered tooling and raw material costs (drill bits being much more expensive than electrode wire). The EDM drilling process also works on extremely hard and tough materials, where traditional drills come up short. The EDM process also shines when extremely long, narrow holes are needed, as traditional drills are often too weak for such tasks.
Since the EDM electrode doesn't have to be rotated, a non-cylindrical hole can be created with the appropriate electrode. One can easily create a precision square or rectangular hole in conductive material. EDM electrodes can be rotated, in applications requiring circular holes. A rotating electrode can be non-cylindrical, creating a round hole, but allowing flushing of worn material in the regions where larger gaps exist between the electrode and the material being machined.
EDM drilling has many applications including machining nickel and titanium based alloys for the aerospace industry. Other applications include drilling on rounded or slanted surfaces.