Small Hole Electrodes

Electrodes in an EDM machine consist of highly conductive and/or arc erosion-resistant materials such as graphite or copper. They can be rods or tubes, multi-channel or single hole, and can vary along all dimensions.

Electrodes for small-hole EDM machines, or “hole poppers,” are normally either brass or copper and are material used to make a hole in the material. The type of hole varies by electrode. They can either be a single hole diameter that has no other internal walls or a multi-channel type internal hole with multiple walls throughout the length of the electrode.

We offer single channel tubing, usually used for through hole applications and multichannel tubing, typically used for “blind holes” in Copper and Brass with OD’s as small as .003″ (single) and .0157″(multichannel). We offer solid rods in both materials and as the diameter gets larger we offer up to 36″ in length.

When working with more exotic metals you might consider Copper Tungsten or Tungsten Carbide as your electrode material. Saturn offers both in tube, Roto tube and solid rods. Copper Tungsten OD’s from .009″ and Tungsten Carbide OD’s from .003″. Our copper tungsten rod and tube stock have a standard grade of 70/30, but we can offer the same sizes in 60/40, 75/25, 85/15. We offer Pure Tungsten solid rod in diameters from .003″ to .250″ in lengths up to 18″.

Over the years we have invested time and money in the best manufacturing and inspection equipment available. Our standard OD and diameter tolerance is+/­.0002″ but in some materials we can offer a diameter tolerance of +/-.00002″!

Single Vs. Multi-Channel Electrodes

One of the main variations between electrode types are whether they are a single hole diameter or a multi-channel electrode. An electrode’s intended performance depends on the type of hole going through the center of the electrode, as different channel types are made of different purposes.

Single Hole Electrodes

A single hole electrode is named for its singular, empty hole diameter. There are no other internal walls within the electrode. They are used primarily for hole burning applications that require a hole to be drilled entirely through a part or material. Because they do not use any internal wall, they require less material to make and are usually less expensive.

Multi-Channel Electrodes

Multi-channel electrodes are designed with internal channels that are used to drill blind holes and burn away excess material at the bottom of the hole. Because of the internal walls, as the electrode spins, it affects every part of the workpiece, leaving no material at the bottom.

Multi hole electrodes come in several variations. These include:

  • Two and Three Channel: Depending on the size of the electrode, it will need a different number of channels for greater structural integrity. If the external diameter is larger, it will have three channels.
  • Wire Inserts: These are inserted into single hole electrodes to make them function similar to a two or three channel electrode. They burn away more material than a single channel.
  • Y-Type and Web Type Electrodes: These electrodes are similar to the two and three channel electrodes in purpose and design, but they use less material and more flushing.

We are the only company to make Graphite rods as small as .007″ diameter. Saturn can provide graphite and copper graphite round electrodes in grades from all the industry’s leading graphite manufacturers.