Electrical Discharge Machining, or EDM, is a process that uses electricity to vaporize metal in a localized area. There are several different kinds of EDM machinery on the market, and knowing as much as possible about each is key to choosing the right piece of equipment for your needs. Today, I’d like to tell you a bit about EDM hole drilling machines.

How Do EDM Drilling Machines Work?

EDM drilling operates much like any other EDM process, just with the difference that the EDM hole driller is optimized to produce semi-accurate holes in ductile materials at high speeds—regardless of the material’s hardness.

As with other EDM processes, in EDM hole drilling, a flushing liquid (or dielectric) is required to wash away the eroded particles from the cut. To achieve this, it’s necessary to deliver the flushing liquid to the very bottom of the hole being cut. This, in turn, requires a drilling electrode that has a thru-hole—sometimes referred to as a tube—to allow the fluid to pass the electrode consistently and easily.

Why Use an EDM Drilling Process?

The major benefit of using EDM drilling machines is that, unlike regular drilling machines that rely on physical force to push a tool through the workpiece, it doesn’t matter how hard the material being drilled is. Whether the material is diamond hard or paper soft, it will yield to drilling process with nearly the same level of ease. With physical drilling machines, the tool can quickly wear out when drilling harder materials—which can be less than ideal when you need to rapidly drill holes in high-hardness objects one after the other.

The drilling tubes used by EDM hole drillers is typically a low-cost yet highly-conductive material—such as brass or copper. This helps keep the costs for replacing worn out EDM drilling tubes down to a minimum.

The depth that a hole can be drilled can be influenced greatly by the size of the drilling tube. Typically speaking, the effective drilling depth of an EDM drilling machine is about 200-250 times the size of the tube’s hole. Hole diameters in these tubes can range from 0.01” to 3/16” (0.1875”). Theoretically, this means that maximum drilling depths could range from 2” to 46.875” deep.

There are some EDM drilling systems available that can perform 5-axis machining to create holes at different angles for specialized applications.

What Are EDM Hole Drillers Used For?

Common uses for EDM hole drilling machines include broken tap/drill/reamer extraction, wire EDM hole starting, and creating cooling holes in aerospace engine components—in addition to simple hole drilling for other applications.

Some industries that can benefit from using EDM drilling machines include the aerospace, energy, general manufacturing, tool & die, mold making/repair, and medical/healthcare industries.

Looking for an EDM hole drilling machine for sale? Contact the experts at SFMS for help finding the right EDM hole driller for your needs!

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