| D CODE | Coded number, following the D address, that specifies a tool offset number
(machining center).
|
| DAMPING | A
characteristic
built
into
electrical
circuits
and
mechanical
systems
to
prevent
rapid
or
excessive
corrections
which
might
lead
to
instability
or
oscillatory
conditions
|
| DATA
BASE | Comprehensive
files
of
information
having
a
specific
structure
such
that
they
are
suitable
for
communication,
interpretation
and
processing
by
both
human
and
automatic
means
|
| DATA
POINT | A
programmed
point
which
contains
tool
plant
co-ordinate
data
and
functional
information
|
| DATA | Facts
or
information
prepared
for
processing
by,
or
issued
by,
a
computer
|
| DATA PROTECTION KEY | Key provided to protect programs, offset values, parameters, and setting data
from being inadvertently registered, altered, or deleted.
|
| DEAD
BAND | The
range
through
which
an
input
can
be
varied
without
initiating
response,
usually
expressed
in
percent
of
span
|
| DEAD
TIME | The
interval
between
initiation
of
a
stimulus
change
and
the
start
of
the
resulting
response
|
| DEAD
ZONE | A
range
of
inputs
for
which
no
change
in
output
occurs
|
| DEAD SMOOTH | The term applied to the finest cut of a
file.
|
| DEBUG | To
detect,
locate,
and
remove
mistakes
from
computer
software
or hardware
|
| DEBURR | To remove sharp edges.
|
| DECADE
SWITCHING | Use
of
a
series
of
switches
each
with
ten
positions
with
values
of
0
to
9,
in
which
adjacent
switches
have
a
ratio
of
value
of
10:1
|
| DECADE | A
group
of
assembly
of
ten
units
|
| DECALESCENCE | A decrease in temperature that occurs
while heating metal through a range in which change
in structure occurs.
|
| DECIMAL
CODE | A
code
in
which
each
allowable
position
has
one
of
10
possible
states.
(The
conventional
decimal
number
system
is
a
decimal
code.)
|
| DECIMAL POINT PROGRAMMING | Entering numeric data using a decimal point.
|
| DECODER | A
circuit
arrangement
which
receives
and
converts
digital
information
frcm
one
form
to
another
|
| DEDENDUM | The depth, or that portion of a gear tooth
from the pitch circle to root circle of gear.
|
| DEDICATED | Devoted
to
a
particular
function
or
purpose
|
| DEPTH OF CUT | Depth of Cut denotes how much material is being removed from a work piece with each pass of the tool.
|
| DESCRETE | State
of
being
separate
or
distinct,
as
opposed
to
a
continuously
varying
state
or
condition
|
| DEVIATION | The
error
or
difference
between
the
instantaneous
value
of
the
controlled
variable
and
the
setpoint
|
| DIAGNOSTIC
ROUTINE | A
programme
which
locates
malfunctions
in
hardware
or
software
|
| DIAMETER PROGRAMMING | Programming for turning in which the amount of movement along the X-axis
(or coordinates) is represented using diameters.
|
| DIAMETRAL PITCH | Ratio of the number of teeth on a
gear to the number of inches of pitch diameter or the
number of teeth to each inch of pitch diameter.
|
| DIE | A tool used to form or stamp out metal parts,
also, a tool used to cut external threads.
|
| DIE STOCK | The frame and two handles (bars) which
hold the dies (chasers) used for cutting (chasing)
external screw threads.
|
| DIGITAL
COMPUTER | A
computer
that
operates
on
symbols
representing
data,
by
performing
arithmetic
and
logic
operations
|
| DIGITAL | Representation
of
data
in
discrete
or
numerical
form
|
| DIGITAL-TO-ANALOG
(D-A)
CONVERSION | Production
of
an
analog
signal,
whose
instantaneous
magnitude
is
proportional
to
the
value
of
a
digital
input
|
| DIGITIZE | To
obtain
the
digital
representation
of
a
measured
quantity
or
continuous
signal
|
| DIGITIZER | Scans and maps the surface of a real object, producing a 3D computer model for CAD/CAM programs.
|
| DIMENSION WORD | Word that represents an amount related to axis movement. It can be an axis
movement destination or an arc radius.
|
| DIRECT DRAWING DIMENSION PROGRAMMING | Operating the CNC based on a program that uses line angles, chamfer values,
and corner R values on machining drawings.
|
| DIRECT INPUT OR TOOL OFFSET VALUE MEASURED B | Automatically setting a tool offset value or workpiece coordinate system shift
value in a CNC for a lathe by manually operating the tool.
|
| DIRECTOR | A
term
used
to
designate
an
NC
control
unit
|
| DIRECTORY | List of files.
|
| DISCRETE
COMPONENT
CIRCUIT | An
electrical
circuit,
implemented
with
individual
transistors,
resistors,
diodes,
capacitors,
or
other
components
|
| DISK
MEMORY | A
non-programmable,
bulk
storage,
random
access
memory
consisting
of
a
magnetizable
coating
on
one
or
both
sides
of
a
rotating
thin
circular
plate
|
| DISK | A
device
on
which
information
is
stored.
|
| DISPLAY | Lights,
annunciators,
numerical
indicators,
or
other
operator
output
devices
at
consoles
or
remote
stations
|
| DISTANCE TO GO | The remaining amount of movement specified in a block.
|
| DISTRIBUTED
COMPUTER
NETWORK | A
collection
of
computers
which
can communicate
with
each
other
|
| DISTRIBUTED
PROCESSING | The
processing
of
information
on
a
distributed
computer
network
in
such
a
manner
as
to
improve
the
overall
efficiency
of
the
task
|
| DISTRIBUTION AMOUNT | Number of pulses to be distributed during pulse distribution.
|
| DITHER | An
electrical
oscillatory
signal
of
low
amplitude
and
of
a
predetermined
frequency
imparted
to
a
servo
valve
to
keep
the
spool
from
sticking
|
| DIVIDERS, SPRING | Dividers whose legs are held
together at the hinged end by the pressure of a Cshaped spring
|
| DIVIDING HEAD (INDEX BEAD) | A machine tool holding
fixture which positions the work for accurately
spacing holes, slots, flutes, and gear teeth and for
making geometric shapes. When geared to the table
lead screw, it can be used for helical milling
operations.
|
| DNC | (Direct
Numerical
Control) Numerical
control
of
machining
or processing
by
a
computer
|
| DNC OPERATION | Automatic operation based on a program being loaded into the CNC via an
interface. In this operation, the program to be loaded can be specified, and
the CNC can be operated based on the specified execution sequence and a
specified execution count.
|
| DO-ALL SAW | A trade name given to a type of band
saw used for sawing metal.
|
| DOCUMENTATION | The
group
of
techniques
necessarily
used
to
organize,
present,
and
communicate
recorded
specialized
knowledge
|
| DOG | A clamping device (lathe dog) used to drive
work being machined between centers. Also, a part
projecting on the side of a machine worktable to trip
the automatic feed mechanism off or to reverse the
travel.
|
| DONNTIME | The
interval
during
which
a
device
is
inoperative
|
| DOUBLE
PRECISION | The
use
of
two
computer
words
to
represent
a
number
|
| DOVETAIL | A two-part slide bearing assembly used in
machine tool construction for the precise alignment
and smooth operation of the movable components of
the machine.
|
| DOWEL | A pin fitted or keyed in two adjacent parts to
accurately align the parts when assembling them.
|
| DOWN FEED (CLIMB CUTTING, CLIMB MILLING) | A seldom used method of feeding work into milling cutters. The work is fed in the same direction as the portion of the cutter which comes in contact with it.
|
| DRESSING | The act of removing the glaze and dulled
abrasives from the face of a grinding wheel to make it
clean and sharp
|
| DRIFT | An
undesired
change
in
output
over
a
period
of
time,
which
is
unrelated
to
input,
operating
conditions,
or
load
|
| DRILL | A pointed tool that is rotated to cut holes in
material.
|
| DRILL (TWIST) | A commonly used metal-cutting drill,
usually made with two flutes running around the
body
|
| DRILL BUSHING | A hardened steel guide inserted in
jigs, fixtures, or templates for the purpose of
providing a guide for the drill in drilling holes in their proper or exact location
|
| DRILL CHUCK | A device used to grip drills and attach
them to a rotating spindle.
|
| DRILL JIG | A jig which holds parts or units of a
structure and, by means of bushings, guides the drill
so that the holes are properly located.
|
| DRILL PRESS | An upright power-driven machine for
drilling holes in metal, wood, or other material.
|
| DRILL PRESS, RADIAL (RADIAL DRILL) | A machine tool for
drilling holes. The drill head is so supported that it
may be moved over a large area to drill holes in
objects of large size or to drill several holes in an
object without shifting the object.
|
| DRILL ROD | A high-carbon steel rod accurately ground
to size with a smooth finish. It is available in many
sizes and is used extensively in tool making.
|
| DRILL SLEEVE | An adapter with an internal and external
taper which fits tapered shank tools such as drills or
reamers to adapt them to a larger size machine
spindle.
|
| DRILL SOCKET | An adapter similar to a sleeve except
that it is made to adapt a larger tapered-shank tool to a
smaller size spindle.
|
| DRILL, TWIST | A commonly used metal-cutting drill,
usually made with two flutes running around the
body.
|
| DRILLING MODE | Mode in which a hole can be machined.
|
| DRIVE FIT | One of several classes of fits in which parts
are assembled by pressing or forcing one part into
another.
|
| DRIVER | A
programme
or
routine
that
controls
external
peripheral
devices
or
executes
other
programmes
|
| DRY RUN | Operation for program testing with no workpiece attached. A feedrate can be
selected manually to override a programmed feedrate.
|
| DUCTILITY | The property of a metal that permits it to
be drawn, rolled, or hammered without fracturing or
breaking.
|
| DUMP | To
copy
the
present
contents
of
a
memory
onto
a
printout
or
auxiliary
storage
|
| DWELL | A
timed
delay
of
programmed
or
established
duration,
not
cyclic
or sequential,
i.e., not
an
interlock
or
hold.
|
| DWELL | Deferring the execution of the next block by a specified period.
|
| DYNAMIC
GAIN | The
magnitude
ratio
of
a
steady
state
output
to
a
sinusoidal
input
signal
|
| DYNAMIC GRAPHIC DISPLAY | Drawing a programmed tool path and a target figure on the CNC screen.
|