Machine tool
It performs the purely mechanical functions and, along with the dielectric system and the power supply, makes up the complete EDM.
Machining rate
Same as Metal removal rate. The rate at which material is removed from the work piece by EDM.
Mean overcut
The average of top and bottom overcut.
Medium
A class of EDM graphite materials characterized by a particle size from 21m to 100m, anisotropy, non-uniform performance, and high porosity.
Metal Removal Rate (MRR)
The rate at which material is removed from the work piece by EDM. In the U.S., usually expressed in cubic inches/hour (in/hr).
Metallic composite
A non-alloyed combination of metals, such as copper tungsten.
Microfarad
One-millionth of a farad. See Farad.
Micron, micrometer (m)
A unit of length equal to one-millionth of a meter.
Microinch (min)
One-millionth of an inch (0.000001").
Micro ohm (mW)
One-millionth of an ohm (0.000001 ohm).
Microprocessor
A computer-on-a-chip. Found in all advanced EDM systems, the microprocessors provide many control functions.
Microsecond (ms)
One-millionth of a second (0.000001 sec.).
Mil
One thousandth of an inch (0.001").
Millisecond (ms)
One thousandth of a second (0.001 sec.).
Miss
A pulse that does not produce machining due to too great a gap.
Modular construction
When used in EDM, a type of power supply where entire circuits are integrated on boards or modules. This type of construction provides a simple and rapid method of servicing and replacing electronic circuits in the field.
Monitor
In EDM, any mechanical or electrical device which is used to indicate various operating conditions, i.e., ammeters, indicators, lights, pressure gages.
Multiple electrodes
The simultaneous use of electrodes to produce multiple cavities in one or more work pieces.
Multiple lead (Multilead) power supply
A standard power supply usually has one wire lead which can be connected to the electrode or work piece and through which the total power available can be channeled. With a multilead power supply, it is possible to divide the total power available into small units, each capable of being channeled through separate wire leads connected to multiple electrodes or work pieces for production work. Or, all power can be put through a single wire lead by connecting all the individual leads into one.