MDM technology uses graphite electrodes depending on the type of burn required.
The electrode in the machine vibrates up and down at a rate of 3,600 times per minute. Each time the electrode touches the piece to be burned, an arc is struck. The arc has a temperature at point of contact of approximately 5,300 ° F. A constant supply of fresh water is pumped down through the electrode causing the molten metal to thermally break down and, at the same time, flushes the thermally shocked metal back out the discharge hole.
The discharged pieces are normally less than 10 microns in size – smaller than a grain of sand. The water also acts as a heat exchanger; the only portion to get hot is the small area in contact with the tip of the electrode, unlike drilling where heat from the bit transfers to the matted portion. The MDM maintains everything at ambient temperature, except what needs to be removed.