Small Hole EDM

Small Hole EDM

Small hole EDM, also known as fast hole drilling and start hole drilling, is a tooling method that uses electrical energy to erode materials and produce holes. Small hole drilling can be used as an independent drilling process or to make a through hole as a pretreatment for wire EDM. Small hole drilling capabilities extend from .03mm to 6.1 mm holes and some can drill through 100 mm of soft or hard materials in less than ten seconds. Small hole EDM services are used in industries including automotive, injection molding, tool and die, medical and appliance with a wide variety of applications such as removing broken drill bits, small hole placement, hardened punch ejector holes and aircraft cooling holes.

Small hole EDM drilling employs a round, hollow electrode that rotates around a spindle, similar to a drill and drill bit. A servo-controlled generator is used to electrically charge the electrode and produce a series of electrical discharges, or sparks. The electrode and the workpiece, or material being processes, is the connected when the tool electrode" forms an arc to the "workpiece electrode" as the two are brought closer together, creating the intense electric field which is responsible for removing material. Dielectric fluid, which prevents premature sparking and flushes away debris, is used throughout the process to flushes out the melted material and provides a controlled environment for sparks to jump from electrode to workpiece. The sparks erode the surface of the workpiece by creating microscopic pockets that eventually create a small hole. CNC machines are used to control the depth and location of the holes during the EDM drilling process, as well as CAD and CAM software.

Small hole EDM can be used for any hard or soft electrically conductive materials, which include stainless steel, titanium, aluminum, copper, carbide and hard tool steels. Some advantages that come with using small hole drilling services include the ability to drill on curved or angled surfaces, to drill through extremely hard materials and to drill very deep holes, while remaining a fast, accurate and affordable process. However, there are some drawbacks to using small hole EDM which include a much longer drilling time for large holes compared to conventional drilling, inability to control blind hole depth and significant electrode wear.

Small Hole EDM Images Provided by Wire Cut Company, Inc.

Small Hole EDM Image Provided by Milco Wire EDM, Inc.