Electrode Tube

Another variable which determines the ultimate success of the electrode properly EDM Hole Burning through the material or work piece is if the Brass Electrode or Copper Electrode tube has a “single hole” or a “multi channelled hole” running directly through the ID or (Internal Diameter) of the electrode.
Basically put; in order for an electrode to perform the way it’s supposed to, it depends on the type of hole going through the centre of the electrode. This type of hole has a few purposes. One purpose is to direct water or coolant through the centre of the electrode. This keeps the entire length of the Brass or Copper Tube from overheating and burning up. If the electrode heats up too much it can become “soft” and warp thus not creating a straight line or a consistent and accurate EDM Hole.
The main reason that determines whether an EDM Electrode tube would have a “single hole” or a “multi-channel” “coreless” hole is that when a hole is EDM Machined into a part it could be a “thru hole” or a “blind hole”. Blind holes are not drilled complete to the other side so a “slug” or a piece of material is still left untouched at the bottom of the hole.