When holes must be drilled on curved, spherical or angled surfaces, great difficulties arise with conventional drilling. Drills tend to walk off of such surfaces. To prevent this, fixtures and guide bushings must be used. With EDM drilling, the electrode never contacts the material being cut, thus eliminating the tool pressure normally experienced when drilling on curved or angled surfaces. EDM drilling is especially useful for drilling straight or angled holes in surgical or medical grade tubing through one or both sides.
Some materials are too hard to drill using conventional methods. The EDM machine drills through almost any conductive material including carbide and hardened steel. Since the chips are constantly flushed with EDM drilling, speed, accuracy and concentricity can be maintained.
Easily drills through soft materials that usually produce gummy chips that stick to cutters, like soft copper and aluminum. Some soft metals can produce gummy chips, leading to problems with conventional drilling. Since the chips are microscopic small and they are constantly flushed with EDM drilling, speed, accuracy and concentricity can be maintained.
Deburring holes drilled by conventional methods can take longer than the drilling. EDM drilling creates no burrs. This burr-free drilling saves time and labor, and is especially crucial when difficult holes are being drilled. In addition, surface finishes are better with EDM drilling. The smaller the hole, the more important a smooth surface is. By reducing the discharge energy, holes can be polished.
Drilling small, deep holes with conventional methods is often extremely difficult if not impossible. EDM drilling is often the only practical method for producing such holes. As conventional drills enter or exit, they can break if torque is not carefully controlled.
With conventional drilling small broken drills are often difficult to remove from the work piece, and time is wasted replacing broken drills and parts may have to be scrapped.
EDM drilling prevents broken drills, it prevents complications in drilling that traditional drilling can't avoid due to improper control of torque conditions. Torque conditions don't exist in EDM because the electrode never touches the workpiece; hence, broken drills become a thing of the past.
Straight holes are produced because EDM drilling utilizes a non-contact process that avoids drifting in drills. And,