To auto-thread the wire in Wire EDM machining, C&C EDM uses EDM Small Hole Drilling to make a through-hole in work pieces. EDM Hole Drilling machines, also known as a super drill or hole poppers, have an x–y axis so that they can machine blind through-holes.
EDM drills bore holes with a long brass or copper tube electrode that rotates in a chuck with a constant flow of temperature-controlled, deionized water flowing through the electrode as a flushing agent and dielectric. The electrode tubes have a spark gap and wear rate, and operate like the wire in Wire EDM machines. Small Hole Drilling EDMs are able to drill through 100mm of soft or hardened steel in less than 10 seconds, averaging 50% to 80% electrode wear rate. Holes of 0.3mm to 6.1mm can be achieved with this drilling operation.
Although very similar to a conventional drilling operation, C&C EDM’s small hole EDM offers many advantages. Delicate parts are feasible for drilling since EDM produces minimal machining forces. Performance is also not affected negatively by hardness or angle of entry. The holes produced by small hole EDM are absolutely burr-free.