Electro Arc Metal Disintegrators can use any material that conducts electricity as an electrode. However, different materials offer varying levels of efficiency in the process. These materials include Copper, Molybdenum, and Graphite electrodes.  Any tubing material that conducts an electrical current can be used as an electrode. However, ELECTRO ARC molybdenum electrodes are recommended because of their high melting point, low erosion, and high conductivity which deliver maximum performance.

It is important to use an electrode material that breaks down less than the workpiece. Materials with low melting points, such as copper, erode as rapidly as the work material, requiring frequent replacement,  increasing your labor cost.  Graphite can be excellent for applications which require shaped holes and to cut at high-temperature applications.  The issue of which material is most efficient in the metal disintegration process has always been a hot topic among metal disintegrator manufacturers.  Elox recommended the use of copper electrodes because of their lower cost.  They also argue that moly electrodes tend to split at smaller diameters and can become jagged which is easy to drill away.

Uni-Tek often sided with Elox regarding copper electrodes saying that they are preferred for use with EDM machines and DC machines because they are highly conductive and fast cutting. Copper electrodes will usually cut most types of work. Molybdenum electrodes have always been recommended for use with Electro Arc metal disintegrators because of their high melting temperature which outperforms other electrode materials.  Electro Arc provides molybdenum electrodes in a variety of sizes and lengths; most electrode sizes are available in 6″, 9″, or 12″  length.  You can use a 12″ long electrode to remove 35 to 40 taps on average.  Special electrodes can be made, including custom sizes and lengths.  Please contact us with your specifications.

Electrodes for your Electro Arc metal disintegrator are available in Molybdenum (moly), Copper, Carbon, Graphite, and Copper Tungsten. Electrodes are available in standard round or square, hex and in special shapes.  Graphite electrodes are recommended for use with production hole work, large quantities of studs, and special applications where the hole definition is critical.  They are also helpful in creating shaped holes and disintegrating at a larger diameter.  Moly is especially beneficial when cutting broken carbide tooling.

Electro Arc provides sizing charts of the appropriate electrode diameter for a variety of tap and drill sizes, for use in removing bolts, spiral, pipe, and heli-tap taps when using AC machines, DC machines and The Bolt Eater.

Sizing Electrodes for your job:

The EDM cutting process has the over-cut phenomenon which you need to consider when sizing your electrodes.  Over-cut is the distance between the electrode and the workpiece after machining has taken place.  In general metal disintegrators have an over-cut range of .003 inches to .008 inches per side.  You can determine the over-cut using the following machine settings:

  1. Cutting power selection (voltage)
  2. Feed Rate (cutting amperage)
  3. Head vibration selection

You can combine 1 and 2 to increase or decrease your over-cut, and feed rate will have little effect on the over-cut.

For example, if you are cutting a 1-inch square hole in hardened steel, you will want to use a square electrode .984″ x .984″ and adjust the cutting power in the higher range to achieve a .008″ per side over-cut.  You can reduce the over-cut and achieve a smoother finish by reducing your cutting power.  This will extend your cutting time.  The depth of your cut and wear ratio of the electrode to workpiece will determine the actual length of electrode you need.

You will need a shank for any electrode larger than .312 because it will not fit in our collet.  You can also use an extension for deeper holes.  Shanks are brazed using steel shanks for moly and copper or brass for copper tubing.  Electro Arc Electrodes are Part Number 1602-06 through A1746, you can request a quote for electrodes online, and you can purchase collets and other accessories for your Electro Arc metal disintegrator through our website.

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