| A [
Words starting with A ] |
| Amperage (A) |
The current that actually machines material
in EDM. |
| Angstrofine |
An advanced grade of EDM graphite characterized
by a particle size of less than 1 micron (0.000039")
and having very high tensile strength, isotropy,
and uniform structure. |
| Anisotropic |
Exhibiting properties whose values change when
measured along differing axes. |
| Anode |
Often used to describe the cutting tool (electrode)
in the EDM process. The positive terminal of an
electrolytic cell or battery. |
| Arc |
A continuous flow of electrical current, visually
recognizable as a yellow flash, between an electrode
and workplace. An arc will damage both the electrode
and workpiece. |
| Arc guard |
Same as arc suppressor. |
| Arc suppressor |
A circuit in the EDM power supply that reduces
that Guards or Suppresses an arc from occurring. |
| Automatic Tool (Electrode) Changer
(ATC) |
A device used with computer numerically controlled
machine tools (EDM) to change tools automatically
to provide automatic operation. |
| Average current |
The average value of all the minimum and maximum
peaks of amperage in the spark gap, as read on
the ammeter. |
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| B [
Words starting with B ] |
| Billet |
A large, uncut block of graphite, usually the
size as produced by the manufacturer. |
| Blind hole |
Any hole or cavity cut into a solid shape which
does not connect with other holes. |
| Breakthrough |
The exit point of a through-hole cavity. |
| Burning |
Slang term for EDM. |
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| C [
Words starting with C ] |
| Capacitor |
An electrical component that stores current
and discharges when they be come full. Traditionally
used for EDM'ing tough to machine and exotic material.
In some EDM power supplies, a bank of capacitors
are connected across the machining gap. |
| Carbon |
An abundant, naturally occurring element. Often
used in place of the word graphite. Graphite is
a form of the element carbon. There are four forms
of carbon. |
| Catalyst |
A material that causes an increase in the rate
of a reaction due to its presence, but is unchanged
at the end of the reaction. In EDM, catalyst refers
to particulates of that aid in establishing a
current path in the dielectric fluid. |
| Cathode |
In EDM, a term to denote the workpiece, or the
negative terminal of a battery. |
| Center Flushing |
A method of flushing dielectric through a center
hole in an electrode or workpiece. |
| Circuit |
A continuous path of electrical current. |
| Coarse |
A class of graphite characterized by a particle
size of more than 100 µm large pores and voids,
a non-uniform structure, and low strength. Not
recommended as an EDM electrode material. |
| Collet |
A device used to hold round shank electrodes. |
| Colloidal Suspension |
Tiny particles produced during EDM'ing form
a colloidal suspension in the dielectric fluid. |
| Common Metals |
The first group of metallic electrode materials.
Includes copper, brass, and zinc. |
| Composite |
In EDM, copper tungsten is an example of a metallic
composite. The copper and tungsten do not alloy,
but are simply combined together. Copper graphite
is a metallic/carbon composite. |
| Condenser |
Same as capacitor. |
| Conductor |
Any material that will carry electrical current
is a conductor. |
| Contamination |
The accumulation of debris in the dielectric
fluid, which can cause instability and a decrease
in the fluid's dielectric strength. |
| Copper Graphite |
Graphite electrode material that is infiltrated
with copper. Use for very fine detail EDM'ing,
but will also wear faster than standard graphite. |
| Copper tungsten |
A porous tungsten material infiltrated with
cooper. |
| Core |
The slug that remains after EDMing with an electrode
that has a flush hole in it. |
| Coreless Machining |
Refers to the Wire EDM'ing all the material
from a shape by stepping from the center instead
of producing a "slug". Similar to a pocketing
routine in milling. |
| Corner Wear |
In EDM, the comers of the electrode wear the
most. Comer wear is the distance up the electrode
comers that show signs of wear. |
| Crater |
The small circular impressions that are formed
by each individual spark as material is removed
that creates the random EDM'd surface on the workpiece. |
| Inches Cube/Hour (in3/hr) |
The units of measure used to describe the rate
of metal removal from the workpiece. |
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| D [
Words starting with D ] |
| DC Arcing |
Same as arc. |
| DC (Direct Current) |
Constant polarity current, as opposed to Alternating
Current (AC), which changes polarity from negative
to positive in cycles. |
| DDM |
Is the Makino "Process" that produces HQSF (High
Quality Surface Finishes). |
| Deionization |
A return of the condition of the dielectric
to a non-conductive state. Failure to accomplish
Deionization during the off-time of the spark
is responsible for DC arcing. |
| Depth of Craters |
The distance from the peaks to valleys on an
EDM'd surface. |
| Depth-to-diameter ratio |
In small hole EDMing, the ratio of the depth
of a blind hole compared to the diameter of the
electrode used to make the hole. |
| Dielectric Fluid |
In EDM, a liquid medium that fills the gap between
the electrode and workpiece and acts as an insulator
until a specific gap and voltage are achieved.
Used to remove chips and cool the electrode/wire
and workpiece. It It then ionizes and becomes
an electrical conductor, allowing a current (spark)
to flow through it to the workpiece. It also serves
to cool the work and to flush away the particles
generated by the spark. |
| Dielectric Strength |
The voltage at which the insulating qualities
of a material break down. In EDM, a specification
applied to dielectric fluid. |
| Discharge |
The EDM spark. |
| Discharge Channel |
The conductive pathway formed by ionized dielectric
and vapor between the electrode and workpiece. |
| Discharge Dressing |
The process used to dress worn electrodes prior
to finishing. The machine is programmed to move
the worn electrode to a dressing block in the
work tank. After dressing, the electrode is returned
to the cavity for the finishing cut. Often used
for forming micro diameter electrodes for small
hole applications. |
| Disintegrator |
An EDM technology used for removing taps and
other broken tools for salvage purposes. The original
EDM application. |
| Dither |
A slight motion in the machining axis (Z) used
to improve cutting stability on manual EDM machines. |
| Dressing |
The re-machining of the face of an electrode
to sharpen its detail after it has been used to
produce a cavity. Electrodes used to make a through-hole
are often dressed at the worn end. |
| Duty Cycle |
The percentage of the on-time relative to the
sum of the on-time and off-time setting for a
particular cut. |
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| E [
Words starting with E ] |
| Edge finder |
An electrically activated device on an EDM machine
to aid in the accurate location of the workpiece
with respect to the electrode. |
| EDM |
See Electrical Discharge Milling or Machining. |
| Efficiency |
A measure of EDM performance which varies with
the on and off time settings for an EDM cut. Duty
cycle. |
| Electrical Discharge Grinding (EDG) |
An EDM machine resembling a surface grinder
but Using a wheel made from electrode material.
Can also be done with a horizontal spindle attachment
(mounted on the quill of a conventional EDM machine)
which has a built-in motor drive for the electrode
wheel. |
| Electrical Discharge Machining (EDM) |
A metal removal process using a series of electric
sparks to erode material from a workpiece under
carefully controlled conditions. |
| Electrical Resistance |
The resistance of the flow of electricity through
material. Measured in ohms. |
| Electrode |
The tool in the EDM process. It must be made
from an electrically conductive material. Its
form, or shape, is a mirror image of the finished
form or shape desired in the workpiece, with its
dimensions adjusted to take into account the amount
of over "burn" that occurs. |
| Electrode Growth |
A plating action occurring at certain low wear
settings which causes workplace material to build
up on the electrode, causing it to increase in
size. |
| Electrode Management Technology
(EMT) |
Automatic management of electrodes for replenishment
in flexible manufacturing environment. |
| Electroforming |
An electroplating process used to make metal
EDM electrodes. |
| Electrolyte |
A normally conductive liquid or gas. |
| End Wear |
A reduction in the length of an EDM electrode
occurring during EDM'ing. Can be given as a dimension,
or as a percentage of the original usable length
of the electrode. |
| Eroding |
Material removal by the EDM process. |
| Exit point |
The point at which the electrode pieces the
workpiece in through hole EDM. |
| Exotics |
The third group of metallic electrode material
types used in EDM. Includes all rarely used metals
such as tantalum, nickel, molybdenum, silver and
even gold. |
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| F [
Words starting with F ] |
| Farad |
The unit of electrical capacitance. Used to
rate the energy storing capacity of a capacitor
and usually rated in microfarads. One farad =
the capacitance between whose plates there appears
a potential of one volt when charged by one amp/second. |
| Filtering |
Removal of chips and other debris from the dielectric
fluid before re-circulating it back into the Work
Zone and Spark Gap. |
| Fine |
A class of EDM graphite characterized by a grain
size from 11µ to 20 µ. |
| Finish |
The surface texture produced by EDM'ing. Usually
given in µin Aa or Ra (U.S.). |
| Finish or Skim Cut |
The final cut made with EDM on the workpiece.
Therefore, roughing cuts, done with conventional
equipment or with EDM, should be planned to leave
only enough material to be removed by the finish
cut to gain final size and surface finish desired. |
| Fire Extinguisher |
Used in today's advanced EDM Sinking systems
to allow for safer unattended operation. |
| Flashpoint |
The temperature at which any flammable material
will burst into flame an important factor in selecting
a dielectric fluid. |
| Flexural Strength |
A property of a solid material that indicates
its ability to withstand a flexural or transverse
load. |
| Float Switch |
An adjustable float switch that monitors the
depth of the dielectric fluid in the tank. |
| Flush Pot |
A multipurpose box-like fixture which is clamped
to the machine worktable. Primarily used when
EDM'ing through-holes. The workpiece is clamped
to its top, usually over an opening that will
permit an electrode to pass through the workpiece
without interference from the tank's top plate.
It is connected to the dielectric system and can
be used for either suction flushing or pressure
flushing. |
| Flushing |
Describes the dielectric movement through the
spark gap that is necessary in EDM to cool the
electrode/wire and workpiece and remove machining
chips and debris caused by the ED machining process. |
| Flushing Hole |
A hole through the workpiece or electrode used
to introduce dielectric fluid to the gap for flushing
purpose. |
| Flushing Pressure |
The pressure supplied by pumps in the dielectric
system supply fluid to the spark gap. |
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| G [
Words starting with G ] |
| Gap (Spark Gap) |
The distance between the electrode and workpiece
when the spark occurs. |
| Gap voltage |
This can be measured as two different values
during one complete cycle. The voltage, which
can be read across the electrode/workpiece gap
before the spark current begins to flow, is called
the open gap voltage. The voltage that can be
read across the gap during the spark current discharge
is the working gap voltage. |
| Generator |
Another term for EDM power supply. |
| Glazed Finish |
A Makino term that refers to a mirror or reflective
EDM'd surface finish < 6 µinch Ra (1µmRmax) that
is produced when charged particles in the gap
are used with orbital motion to electro-mechanically
polish the surface. Extreme accuracy and rigidity
is required in order to maintain a precise spark
gap. |
| Grain |
In manufactured carbon and graphite product
technology, a region in a carbon or graphite body
that is identifiable as being derived from a particle
or filler. |
| Graphite |
One of the four forms of carbon. In EDM, a material
used for electrodes which has high heat resistance
and transfers electric current very efficiently.
It is the most popular electrode material and
probably the easiest to machine. |
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| H [
Words starting with H ] |
| Head |
That part of the EDM machine tool in which the
quill or Ram (Z Axis) travels. |
| Heat-Affected Zone (HAZ) |
The layer below the recast layer. This layer
has been d subjected to elevated temperatures
that have altered the properties of the material. |
| Hertz (Hz) |
The international term for one complete electrical
cycle or frequency. |
| HQSF™ |
Is Makino's High Quality Surface Finish that
uses Diffused Discharge Machining (DDM) technology. |
| Hunting |
Erratic movement of the EDM quill during a cut
that can be caused by poor flushing conditions
in the gap, servo response set for too much sensitivity,
and build-up of carbon deposits on the bottom
of the cavity being EDM'd. |
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| I [
Words starting with I ] |
| Intelligent Expert System(IES) |
Intelligent Expert System is Makino's software
driven adaptive control system designed to automatically
correct machining variables during machining.
Some EDM builders for their adaptive control system
use "Fuzzy Logic". One weakness is that Fuzzy
Systems are hardware dependant and become obsolete. |
| Injection |
The introduction of dielectric fluid to the
gap under pressure. |
| Injection flushing |
An external flushing method, also known as jet
flushing. Fluid is directed into the gap by means
of a flexible tube. |
| Initiation voltage |
Same as open gap voltage. |
| Insulator |
A substance which blocks the flow of electric
current. |
| Ion |
An atom or group of atoms that carries a positive
or negative charge as a result of having lost
or gained one or more electrons. It is ionization
of the dielectric fluid that provides the conductive
path for the EDM spark. |
| Ionization |
The process by which the dielectric fluid become
electrically conductive between the electrode
and workpiece. |
| Ionization Delay Time |
The inconsistent delay between ionization start
and completion times and is affected by changing
Gap conditions. |
| Ionization Time |
The time from the application of voltage until
current begins to flow. |
| Ionization Voltage |
The voltage at which current flow begins across
the gap. |
| Ionized Path |
The path of electrically conductive dielectric
molecules between the two points on the electrode
and workpiece through which the spark current
will flow. |
| Isotropic |
Exhibiting properties with the same values when
measured along axes in all directions. Opposite
of anisotropic. |
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| J [
Words starting with J ] |
| Jump |
Exhibiting properties with the same values when
measured along axes in all directions. Opposite
of anisotropic. |
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| K [
Words starting with K ] |
| None |
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| L [
Words starting with L ] |
| Lateral Flushing |
Same as surface or splash flushing. Directing
the flow of dielectric fluid through a hose pointed
at the electrode in order to remove chips and
swarf in a [shallow] blind cavity. |
| "LL" Generator |
Is Makino's anti-electrolysis generator and
stands for "Layer Less". |
| Low Wear |
The result of certain settings for EDM machining
which produces a very low degree of wear by plating
the electrode with melted work material. In some
cases less than 1%, which is also known as no-wear.
|
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| M [
Words starting with M ] |
| 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 workpiece by EDM. |
| Mean Overcut |
The average of top and bottom Overcut. |
| Medium Grade |
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
workpiece 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. |
| MG CNC Control |
Makino Graphic CNC Controls. First with GUI
style operator interface and simplified macro
driven software. |
| Micro-farad |
One-millionth of a farad. |
| Micron Machining |
Makino term for precision EDM machining. |
| Micron, Micrometer (µm) |
A unit of length equal to one-millionth of a
meter or 0.00003973" Micro inch (µinch) One-millionth
of an inch (0.000001"). Micro Processor A computer-on-a-chip. |
| Micro second (µs) |
One-millionth of a second (0.000001 sec.) used
to control each EDM spark from the generator µs
of On & Off-Times |
| Millisecond (ms) |
One thousandth of a second (0.001 sec.). |
| Miss |
A pulse that does not produce machining due
to too great a gap. |
| Model Data |
Provides the programmer the ability to pre-select
from 1 to 15 burning conditions (roughing and
finishing) based on electrode size and surface
finish with ONLY two inputs. |
| Model Plan |
Canned Cycles (Macros) that simplify EDM Programming
through the use of commonly used Machining Positioning
and Measuring Models (or Functions) that can be
programmed easily using Makino's Graphic User
Interface. |
| 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 workpieces. A
standard power supply usually has one wire lead
connected to the electrode or workpiece and through
which the total power available. |
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| N [
Words starting with N ] |
| No-Wear |
Defined by POCO as a condition under which 1
unit or less of electrode is eroded to every 100
units of workpiece. (one percent or less) |
| No-Load Voltage |
Same as open gap voltage. |
| Non-Directional Finish |
An EDM finish is non-directional and has no
specific direction to its surface pattern. |
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| O [
Words starting with O ] |
| Off-Time |
The time between sparks, measured in microseconds.
Too short an off-time may result in unstable machining
or worse, DC arcing. |
| Ohm |
A unit of electrical resistance equal to that
of a conductor in which a current of one ampere
is produced by a potential of one volt. |
| Oil-through-chuck |
A sealed holder for tubular electrodes through
which dielectric fluid can be pumped or sucked
for center hole flushing. |
| On-Time |
The duration time of the EDM spark measured
in microseconds. |
| Open Circuit |
An electrical circuit which is not complete. |
| Open Gap Voltage |
The voltage that can be read across the electrode/workpiece
gap before the spark begins to flow. See gap voltage. |
| Operating Current |
Same as average current. |
| Output |
The voltage and current of an EDM power supply. |
| Overburn |
Same as overcut. |
| Overcut |
An EDM cavity is always larger than the electrode
used to machine it. The difference between the
size of the electrode and the size of the cavity
is called the overcut. When discussing or calculating
overcut, be sure to specify whether you are referring
to total overcut (Diametral overcut) or overcut
per side. Diametral overcut is most often used. |
| Overcut, per side |
One-half of the Diametral overcut value. It
is important to follow this procedure in designing
electrodes: (1) Select surface finish settings
to determine finishing cut overcut. (2) Design
finishing electrode size with overcut allowance.
(3) Design roughing electrode providing for overlap
which will leave proper allowance for the finish
machining cut to clean up the surface left by
the rough cut. |
| Overlap |
(1) The area by which the electrode for the
next cut exceeds the workpiece cavity. (2) The
difference between the rough machined hole or
cavity size and the size of the electrode to be
used for the next cut. |
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| P [
Words starting with P ] |
| Particle Size |
The average cross section of the solid graphite
particles in a graphite system. The carbonaceous
material from which the graphite is produced and
the method of manufacturing determine the particle
size. Also referred to as grain size. |
| Pause |
The absence of electrical energy for a preset
time following a discharge of electrical energy
(pulse). |
| Pause Duration (time) |
Same as off-time. |
| Peak Current |
The maximum current available from each pulse
from the power supply/generator. |
| Percent Electrode Wear |
The volume of electrode worn away as compared
to the volume of workpiece worn away. |
| Pieced Electrode |
(1) An EDM electrode made using lower quality
graphite as a base material with a higher quality
material as the cutting surface. Such electrodes
require careful mating to insure conductivity
and correct positioning. (2) An electrode that
has been repaired by replacing a broken part.
All cutting surfaces must be of the same material
for uniform performance. (3) An electrode made
from several pieces of the same quality material
to obtain a bigger electrode. |
| Plasma |
A superheated, ionized gas that forms in the
discharged channel due to the action of the thermoelectric
force. |
| Platen |
A large flat mounting surface affixed to the
end of the quill or the ram of an EDM machine,
and on which the electrodes or various electrode-holding
devices can be mounted. It usually has tapped
holes or machined T-slots for convenience in clamping
electrodes or holders. |
| Polarity |
In EDM, the designation of positive or negative
electrical polarity of the electrode. Positive
polarity of the electrode (in CNC EDM) is considered
to be Normal and produces the least amount of
electrode wear. |
| Potential |
The difference in voltage between two points
of an electrical circuit. |
| Power Supply |
Or Generator. The part of the EDM system that
supplies the voltage and current that causes the
sparks or discharges between the electrode and
workpiece. |
| Premium Graphite |
A material with a particle size of 5 microns
or less. |
| Pressure Flush |
The forcing of dielectric up through flush holes
in the workpiece or down through flush holes in
the electrode. |
| Pretensioned Axis Screws |
The practice of stretching a ball lead screw
by several tenths (0.0001"), between two supports
in order to provide added rigidity, alignment
and accuracy. |
| Pulsator |
A unit on the EDM machine which periodically
causes the electrode to retract for a short period
of time to aid in flushing a deep or blind cavity.
Also commonly called a RAM cycler or jump control. |
| Pulse |
The discharge of a single spark of electrical
current having preset time. |
| Pulse duration (time) |
Same as on-time. |
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| Q [
Words starting with Q ] |
| Quench |
The rapid cooling of the EDM'd surface by the
dielectric fluid. Partially responsible for the
metallurgical changes forming the recast layer
and the heat-affected zone. |
| Quill |
The moving member of an EDM machine on which
the electrode or electrode holder is mounted.
A cylinder working in a bearing or bushing. |
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| R [
Words starting with R ] |
| Ram |
The moving member of an EDM machine on which
the electrode or electrode holder is mounted.
A dovetail guided arrangement. |
| Ram Cycler |
Same as pulser. |
| RC or Relaxation Circuit |
An EDM powers supply (circa 1962) that used
capacitors to produce a spark. This early EDM
power system is seldom used in advanced machines. |
| Recast layer |
A layer created by molten metal solidifying
on the workmetal surface. |
| Reverse Burning |
The technique of mounting the electrode on the
machine table or flush tank and the workpiece
on the quill. Used in EDMing a blanking punch
with female electrode. |
| Rotating Spindle |
Either an accessory mounted on the quill or
ram, or a built-in machine spindle used to rotate
the electrode to achieve more uniform wear and
to improve flushing conditions. Its use is limited
to round electrodes. Another use for the rotating
spindle is in trimming the workpiece with an indicator,
as you would on a jig borer, for setting locations.
|
| Roughing |
The mode of EDM that removes the most material
in the shortest time. |
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| S [
Words starting with S ] |
| Secondary Discharge |
A discharge that occurs as conductive particles
are carried up the side of the electrode by the
dielectric e fluid. |
| Servo Mechanism |
The device that drives and controls the movement
of the quill or Ram. |
| Servo Reaction Time |
The time between a signal to the servo and its
physical response to the signal. |
| Side wear |
In EDM, the wear along the sidewalls of the
electrode. |
| Silicone |
A dielectric fluid for special situations consisting
mostly of the chemical polymer silicone. |
| Silver tungsten |
A porous tungsten material which is infiltrated
with silver. |
| Solid state power supply |
Transistorized circuitry. See transistor. |
| Spark |
An electrical discharge between two conductors. |
| Spark Erosion |
Another name for EDM. |
| Spark gap |
The distance between the electrode and the workpiece
when discharges are occurring. |
| Spark intensity |
The amount of energy in the spark. |
| Spindle |
An upper rotating member of an EDM machine to
which the electrode or electrode holder is mounted. |
| Split electrode |
Multiple electrodes on a single machine electrically
insulated from each other. Used with multiple
lead power supplies. |
| Split lead power supply |
Same as multiple lead power supply. |
| Square wave |
A term for an electrical wave shape generated
by a solid state power supply. |
| Stability |
Refers to the steadiness of EDM cut. The opposite
of hunting. |
| Staged Electrode |
A multiple electrode set designed to produce
a single cavity. From rougher to finisher, each
electrode must have dimensions that take into
account leaving sufficient metal for the last
electrode to produce the required dimensions. |
| Stepped Electrode |
An electrode constructed in such a manner as
to allow the roughing and finishing of a through-hole
cavity in a single set up. The smaller front section
is used to rough out the cavity and the larger
rear portion is used for finishing. |
| Stroke |
The distance the ram/quill travels under servo
control. |
| Sublime |
To pass directly from a solid state to a gaseous
state. Graphite does not melt when heated at normal
pressures, but passes directly into a gaseous
state. |
| Suction Flushing |
Using a vacuum to draw the contaminated dielectric
away from the gap as opposed to forcing it out
with pressure. |
| Superfine |
A class of EDM electrode materials with a particle
size from 6m to 10m characterized by moderately
high strengths, usually isotropic.
|
| Surface Finish |
The surface roughness of a machined surface.
µinRa in the U.S.
µmRmax or µmRy in
Asia
µmRa or VDI in Europe. |
| Surface Integrity |
The quality of the machined surface and subsurface
and has little to do with surface finish. |
| Surface Flushing |
The use of nozzles or hoses to direct jets of
dielectric at the cutting area to flush away the
debris. Usually employed while pulsating the electrode. |
| Surface Roughness |
Surface irregularities on a machined surface.
See finish, surface finish. |
| Swarf |
The eroded particles or residue. |
| Synthetic Dielectric |
Newer types of dielectric oils that are safer
than mineral seal oils used. |
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| T [
Words starting with T ] |
| Taper |
The dimensional difference between the entrance
and exit opening of a cavity, or between the entrance
and bottom of a blind hole. |
| Tellurium Copper |
An alloy of copper and tellurium. |
| Thermal Convectiona |
Temperature Cut-Off A circuit that shuts down
a system at a preset temperature. Used on EDM
dielectric systems. |
| Time Controlled Machining |
Through-Hole Flushing The use of a pre-drilled
hole in the workplace to inject dielectric fluid
up toward the gap by injection flushing or down
from the gap by suction flushing. |
| Total Form Machining (TFM) |
An abrasive machining device capable of copying
complete graphite electrodes. |
| Tramming Attachment |
A mechanical accessory used in EDM to check
the accuracy of the setup and to aid in the precise
location of the workpiece in respect to the electrode. |
| Transistor |
An electronic component used as a switch to
open and close with extreme speed. Replaced the
vacuum tube due to its reliability, long life,
and much higher switching speed. |
| Trepanning Electrode |
A hollowed out or tubular electrode which is
used in through-hole machining to remove a large
amount of material from the solid so as to avoid
pre-machining by conventional means. |
| Tungsten |
A metal used in pure or near pure state as an
electrode material, Melting point is 3380ºC. |
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| U [
Words starting with U ] |
| Ultrafine |
A class of EDM graphite characterized by a particle
size from 1µ to 5µ isotropy, uniform structure,
and high strength. |
| Unstable |
Erratic or intermittent EDMing. |
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| V [
Words starting with V ] |
| Vacuum Flushing |
Same as suction flushing. |
| Vacuum Tube Power Supply |
An EDM power supply which uses vacuum tubes
to switch the electrical machining pulses (sparks)
on and off. |
| Vibrator |
An accessory used on an EDM machine to move
the workpiece or electrode back and forth rapidly.
Employed primarily for improving flushing in blind
cavities. |
| Viscosity |
The tendency of a fluid to resist flow. High
viscosity liquids are thicker. |
| Voltmeter |
An instrument that measures the Average voltage
across the spark gap on an EDM machine during
machining. |
| Volumetric Wear |
The total wear of the electrode expressed in
cubic inches. |
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| W [
Words starting with W ] |
| Wave Form |
A geometric shape that represents the output
of a power supply as seen on an oscilloscope. |
| Wear |
The erosion of the electrode during the EDM
process. |
| Wear Ratio |
The ratio of electrode material volume worn
away as compared to the volume of workpiece material
removed by EDM. |
| Wire EDM |
The electrode is a continuously spooling conducting
wire that moves in preset patterns around the
workpiece. |
| Working Gap Voltage |
See gap voltage. |
| Workpiece |
The part being (EDM) machined by a machine tool. |
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| X [
Words starting with X ] |
| None |
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| Y [
Words starting with Y ] |
| None |
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| Z [
Words starting with Z ] |
| None |
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