POE Glossary of Terms
A
ABET: Accrediting Board for Engineering
and Technology.
Abrading: The process of removing material by applying friction
Abutment: The part of a structure (as an arch or a bridge) that
directly receives thrust or pressure. (0).
Acceleration: Exists when the velocity of a particle changes with
time.
Acceptance level: The maximum number of defects in a sample that will
permit acceptance of the entire lot.
Accumulator: A device (as in a hydraulic system) in which a fluid is
collected and especially in which it is kept under pressure as a means of
storing energy. (0).
Accuracy: Degree of conformity of a measure to a standard value.
Acoustical: Of or relating to the sense or organs of hearing, to
sound, or to the science of sounds. (0).
Actuator: A device that transfers fluid or electrical energy into
mechanical energy.
Adhesion: The process of fastening two parts by the application of a
third material such as glue, epoxy, etc.
Allowable Stress: Level of stress judged to be permissible in a
design.
Alloy: A substance composed of two or more metals or of a metal and
a nonmetal intimately united usually by being fused together and dissolving in
each other when molten. (0).
Alternator: An electric generator for producing alternating current
Analog: Of, relating to, or being a mechanism in which data is
represented by continuously variable physical quantities (0).
Angle: The union of two co-planar rays intersecting at a common
endpoint.
Annealing: The process of softening metal for improved machinability
or cold working by heating it to its critical temperature, holding it there
until the temperature is uniform, then cooling it slowly at a controlled rate.
Arch Bridge: a bridge that uses long span arches for
support” (0).
Assembly: Consisting of individual parts fitted together to create a
final product
ASTM: American Society for Testing and Materials
Attribute Listing: idea generation listing and combining the
attributes associated with a situation.
Austenite: a solid solution in iron of carbon and sometimes other
solutes that occurs as a constituent of steel under certain conditions
Automation: A machine or system that operates with minimal human
control: using automated machines as control for production.
Axial Force:
Force aligned along the central axis of a material.
B
Bar Chart: A graph in which the data is represented by horizontal or
vertical bars.
Beam Bridge: A bridge whose main structural element consists of a
beam set across two or more vertical supporting members. (0).
Bearings: Devices used to reduce friction between rotating shafts and
fixed carriers. Examples are roller, ball, and air bearings.
Belt: A continuous band that transmits motion from one pulley to
another.
Benchmark: A point of reference for making measurements or judgments.
Bernoulli’s Law: A change in the velocity of a fluid caused by a
constriction produces an opposite change in pressure.
Blow Molding: Method of fabrication in which a warm plastic parison
(hollow tube) is placed between the two halves of a mold cavity and forced to
assume the shape of that mold cavity by use of air pressure. (0).
Bonding: Adhering materials with cement or glue
Boyle’s Law: The volume of a gas at a constant temperature is
inversely proportional to its pressure.
Brainstorming: A group problem-solving technique that involves the
spontaneous contribution of ideas from all members of the group; during this
process, ideas are shared but not critiqued. (0).
Brazing: Sometimes called hard soldering. Joining pieces of metal
together below the point of fusion by melting a third
British Thermal Unit (BTU): The US Customary unit of thermal energy;
the amount of energy needed to raise the temperature of one pound of pure water
by one degree Fahrenheit.
Brittleness: The description for a material which is neither ductile
nor malleable and will fail suddenly without warning.
Broaching: a precision machining process used to change the shape of
a hole into another shape (e.g. a square or keyhole); a broach is used to do
this (see pictures below)
Bronze Age: The period of ancient human culture characterized by the
use of bronze that began between 4000 and 3000
B.C. and ended with the advent of the Iron Age.
Buckling: Failure caused by bending, giving way, or crumpling due to
excessive force
C
CAD: computer-aided design; drafting or solid modeling performed on
a computer
Cadmium Sulfide Cell: A light sensitive resistor; also known as a
photocell
CAM: computer-aided manufacturing; aiding in the manufacturing
process through the use of computer technology
Cp: Capability Index, a measure of how capable a machine or process
is to stay within the limits given for that process or machine
Cable-stayed Bridge: A bridge in which the deck is supported on
either side of a central tower or towers by cables. Unlike a suspension bridge,
the cables that hold the deck attach directly to the tower, rather than hanging
from a larger cable running between the towers. (0).
Calendaring: The process of forming plastic sheets by squeezing a
thermoplastic material between a series of rollers.
Caliper: any of various measuring instruments having two usually
adjustable arms, legs, or jaws used especially to measure diameter or thickness
-- usually used in plural <a pair of calipers> (0) see example of
dial caliper below:
Calorie: A metric unit of thermal energy; the amount of energy
needed to raise the temperature of one gram of pure water by one degree Celsius;
A Calorie (capital C) is a “food calorie” and is 1000 calories); 1.00 calorie =
4.186 Joule.
Cam: A mechanical device used to change simple rotary motion into a more
complex motion.
Cam Cycle: one complete 360º rotation of a
cam
Carbide: A compound of carbon with one or more metallic elements.
(0).
Carbon: A nonmetallic chiefly tetravalent element found native (as in
the diamond and graphite) or as a constituent of coal, petroleum, and asphalt,
of limestone and other carbonates , and of organic compounds or obtained
artificially in varying degrees of purity especially as carbon black, lampblack,
activated carbon, charcoal, and coke (Webster.com)
Carburizing: (Cementation) Adding carbon to the surface of iron-base
alloys by absorption through heating the metal at a temperature below its
melting point in contact with carbonaceous solids, liquids or gasses. The oldest
method of case hardening. (0).
Case Hardening: Carburizing and subsequently hardening by suitable
heat-treatment all or part of the surface portions of a piece of iron-base
alloy. (0).
Case study: A broad-based analysis of an engineering problem.
Casting: The process of producing an object by pouring a heated
liquid material into a mold and allowing it to solidify by cooling.
Catapult: A system used to launch objects. (Ancient catapults used
bent wood as the power source, modern systems use power such as steam.)
Cell: A single space for an entry in a spread sheet
Center of Gravity: The point at which the entire weight of a body
may be considered as concentrated so that if supported at this point the body
would remain in equilibrium in any position. (0). Same location as
center of mass.
Center of Mass: The point in a body or system of bodies at which the
whole mass may be considered as concentrated. (0). Same location as
center of gravity.
Centi: a prefix meaning one hundredth or 1/100 or 10-2;
symbol: c
Centroid: A point whose coordinates are the averages of the
corresponding coordinates of a given set of points and which for a given plane
or three-dimensional figure (as a triangle or sphere) corresponds to the
center of mass of a thin plate of uniform thickness and consistency or a
body of uniform consistency having the same boundary. (0).
Cementite: A compound of iron and carbon known as “Iron Carbide,”
which has the approximate chemical formula Fe3C containing 6.69% of carbon. Hard
and brittle, it is the hard constituents of cast iron, and the normal form in
which carbon is present in steel. It is magnetizable, but not as readily as
ferrite. (0).
Center Line: A line consisting of a long dash followed by a short
dash, that is used to show and locate centers of arcs and circles, and to
describe the center axis of cylindrical forms.
Ceramic: A compound of metallic and nonmetallic elements, for which
the interatomic bonding is predominantly ionic. (0).
Chain: A continuous band consisting of metal or plastic links that
transmits motion from one sprocket to another.
Charles’ Law: The volume of a gas at a constant pressure is directly
proportional to its temperature.
Chart: A sheet or map giving information in the form of a table,
list or diagram
Chemical: Of, relating to, used in, or produced by chemistry. (0).
Chemical energy: The energy associated with chemical bonds and
bonding structure. This includes the energy associated with changes in phase
from solid to liquid to gas. Chemical energy does not lend itself to an
equation. Rather, there are tabulated values associated with all known elements
and compounds, as well as values for the most common chemical reactions.
Chronological: Arranged in or according to the order of time.
Circle: A closed curve with coplanar points at the same distance
from the center point.
Class of Fit: Fits are arranged in three general groups known as
running and sliding fits, locational fits, and force fits
Closed loop: The output of a process is constantly monitored and the
input adjusted according to feedback provided by sensors.
Cohesion: The process of fusing two like materials for the purpose of
fastening. Examples include friction welding, spot welding, electron beam
welding and laser welding).
Cold forming: The process of working metal into shape below the
temperature of recrystallization. Cold forming improves the strength;
machinability, dimensional stability and surface finish of metals.
Communication: The act of transmitting useful data or ideas to one or
more receivers; can be one-way or two-way.
Component: A single device or part in an assembly
Component Relational Sketch: A pictogram showing the relationship of
how the components react together in a system.
Composite: A multiphase material formed from a combination of
materials that differ in composition or form, remain bonded together, and retain
their identities and properties. (0).
Compound: A substance of two or more elements in fixed proportions.
Compounds can be decomposed into their constituent elements. (0).
Compression: The effect of a force which tends to shorten an object
in the direction of the force. Such a force is called a compressive force, and
the object it acts on is said to be in compression. For example, the towers of a
suspension bridge are in compression. (0).
Compression molding: A forming process in which a powdered
thermosetting plastic is placed in a heated mold cavity then compressed by a
ram. After being compressed, the plastic solidifies, the ram retracts, and the
part is ejected.
Compressor: A device that converts mechanical force into pneumatic
energy.
Computer aided drafting (CAD): The use of a computer to create
drawings.
Computer Numeric Control (CNC): A combination of a computer, a
digital control system and a machine tool that enables the machine to accept
standard codes and automatically make parts.
Concurrent: Occurring at the same time; running parallel; acting in
conjunction. (0).
Conditioning: The process of treating a material to achieve physical,
electrical, or mechanical properties.
Conduction: (Thermal definition) The transfer of heat energy by
physical contact.
Conflict Of Interest: Moral dilemma from dual responsibilities or
loyalties.
Contour: An outline, especially of something curved or irregular.
Constraints: Restrictions or guidelines.
Contribution: To supply a significant part.
Control Limits: (Lower and upper control limits (LCL
and
UCL)); these describe what the process is actually giving you; they are
random variables that are a function of the process itself; they are observed or
calculated, not set.
Convection: The transfer of heat energy by moving a heated substance
from one place to another.
Conveyer: A belt like device used to move objects.
Coplanar: Occurring in the same plane.
Counter bore: A larger drilled hole concentric with a smaller
diameter hole. The larger hole is not as deep as the smaller hole.
Countersink: A beveled or conical surface at the top of a drilled
hole for the purpose of accepting a bolt head.
Coupling: A system used to connect and transfer energy from one part
to another - usually shafts that rotate.
Crankshaft: A shaft that has journals which changes reciprocating
motion to rotary motion.
Creep: The slow change of dimensions of an object from prolonged
exposure to high temperature or stress. (0).
Critical Component: A component in a system that, if it fails,
renders the entire system useless. In reliability studies, Critical Components
are the focus of improvement efforts.
Critical temperature (points): Temperatures at which internal changes
or transformations take place within a metal either on a rising or falling
temperature. (0).
Crystalline: In some resins a state of molecular structure denoted
by uniformity and compactness of the molecular chains. This characteristic is
attributable to the existence of solid crystals with definite geometric form.
(0).
Current: The total amount of electrons flowing through a circuit per
unit time; measured in Amperes (one coulomb of electrons passing a single point
per second).
D
Data: Information (measurements or statistics) used as a basis for
reasoning, discussion, calculation or transmission.
Data base: 1) Collection of similar information in a computer file; a
data base can be divided into records and fields; 2) A facility which is a
central point for the collection and dissemination of various types of
information.
Deflection: A measure of deformation of a structure due to applied
loads
Deformation: Change in size and/or shape of a body due to stress.
(0).
Delphi Technique: Individuals contribute solution ideas independently
to a central office.
Delta: Greek letter 
used
in mathematical formulae to represent change.
Design: Translation of a concept into a satisfactory, producible,
salable form.
Design brief: A format for stating a design problem.
Design Constraints: Requirements and limitations under which the
design process takes place.
Desktop Publishing: Creating and publishing a document using a PC and
output device such as a laser printer.
Destructive Testing: Material or product testing in which
information is learned about the material/product via careful measurements and
recordings as the material/product is destroyed.
Detail: Shape or feature on a model.
Deviation: The difference between the actual measurements of a
product and the design specifications.
Diagonal: A line that is slanting or oblique
Dial Indicator: A precision measurement device accurate to at least
one thousandths of an inch used to measure inside and outside dimensions and
depths of materials with the output being read using a dial.
Diaphragm: Part of a pump that consists of a flexible membrane.
Digital: An information system whose signals have only two states, 1
(closed) or 0 (open).
Dilemma: A choice between equally unpleasant courses of action.
Dimension Line: Thin line segment capped on the ends with
arrowheads, that indicate the length of the dimension.
Dimension: Numerical value used on a drawing to describe location,
size, shape, or geometric characteristic.
Dimensioning: The process of placing measurements and notes on a
drawing to completely communicate its meaning.
Dimensional: A measure in one direction; specifically: one of
three coordinates determining a position in space or four coordinates
determining a position in space and time. (0).
Discipline: An area of study
Displacement Diagram: (Re: cams) A drawing that represents the
desired motion of the cam. The length of the diagram is equal to the
circumference of the working circle. The height of the diagram is equal to the
radius of the working circle. The length of the diagram is divided into
intervals representing degrees of rotation of the cam, a common interval would
be 30 degrees. The smaller the interval, the more accurate the cam profile:
Displacement: Movement of an object through a distance.
Drilling: To bore or drive a hole in. A machining process that
produces a hole (0)
Ductility: Property of materials that will undergo plastic
deformation or elongation of more than 5% before fracture.
Dwell: That segment of cam rotation that causes the follower to
remain stationary
Dynamics: The behavior of matter when in motion; (physics) the study
of why objects move.
E
Eccentric: A device that rotates in an off-center position on an axle or
shaft.
Edge: The line where two surfaces or points intersect.
Elastomers: Any of various elastic substances; An amorphous,
cross-linked high polymer that will stretch rapidly under tension, reaching high
elongations (500 to 1000%) (0).
Electron Discharge Machining (EDM): A separating process that
produces a spark between an electrode and the work piece causing an erosion
action. This process can only be used on electrically conductive materials.
Elastic Modulus (Young’s Modulus or the Modulus of Elasticity): The
ratio of stress to strain when deformation is totally elastic; also a measure of
the stiffness of a material. (0).
Elastic Potential Energy: The energy that can be stored in the
compression or extension of an elastic material (traditional springs included).
The equation for the energy stored in a spring is SE= ½ kx2 where
“k” is the spring constant (or modulus of elasticity for a solid ) and “x” is
the distance of extension or compression.
Electromagnet: A core of magnetic material surrounded by a coil of
wire through which an electric current is passed to magnetize the core. (0).
Electromagnetic energy: The energy associated with electricity,
magnetism, and electromagnetic waves.
Elastomer: A polymeric material that may experience large and
reversible elastic deformations. (0).
Electrical: Of, relating to, or operated by electricity. (0).
Electrode: A conducting element that emits or collects electrons or
ions or controls their movement
Electronic: The use of electronics to control a system or machine.
Element: A substance that cannot be decomposed into simpler
substances by chemical means. (0).
Ellipse: The group or set of all points in the same plane whose sum
of distances from two points (foci) is constant. An ellipse looks like a
squashed circle or a circle viewed at an angle.
Engineering: A course of study followed by a professional career that
involves complex analysis, design and development of solutions to technical
problems.
Engineering technology: A course of study followed by a professional
career that involves testing, troubleshooting, servicing and maintenance of
technical product sand systems.
English system: (U.S. Customary System) A measurement system in which
the fundamental units are the foot, slug, and second
Environment: The ecological community that one lives in
Equilibrium: A state of balance due to the equal action of opposing
forces in a structure. (0).
Essence: The quality or nature of something that identifies it or
makes it what it is.
Ethics: a. a set of moral principles or values b. a
theory or system of moral values <the present-day materialistic ethic>
c. plural but singular or plural in construction : the
principles of conduct governing an individual or a group <professional ethics>
d. a guiding philosophy. (0).
Eye Contact: Visual contact with another person's eyes
Experimentation: Developing a solution by conducting experiments and
gathering information.
Extension Line: Thin lines used to establish the extent of a
dimension.
Extrusion: A forming process which uses force to push material
through a die to give it a specific cross sectional shape.
F
Factor of Safety (FOS): The ratio of ultimate or yield stress
(depends on the material and standards people use) to allowable stress.
or 
Failure: A fracturing or otherwise not performing due to stress or
outside events
Fall: (Re: cam) That segment of cam rotation that causes the
follower to move downward
Fatigue: The failure or decay of mechanical properties after
repeated applications of stress. Fatigue tests give information on the ability
of a material to resist the development of cracks (which eventually bring about
failure) as a result of a large number of cycles. (0).
Fastening: The joining of two or more parts or materials through the
application of mechanical devices, adhesive materials or a cohesive process.
Feature: Any physical portion of an object, such as a hole or fillet.
Ferrite: any of several magnetic substances that consist essentially
of ferric oxide combined with the oxides of one or more metals (as manganese,
nickel, or zinc), have high magnetic permeability and high electrical
resistivity, and are used especially in electronic devices. (0).
Ferrous: Related to iron (derived from the Latin ferrum); iron base
alloys. (0).
Free Fall: Where an object moves freely under the influence of
gravity
Freehand: Done without the use of tools or drawing equipment.
Filter: A component used to remove impurities from air or liquids.
Finishing: The final processes applied during the production or a
part. (examples include coating, de-burring, blast finishing, coloring,
cleaning, etc.)
Firing Angle: The angle in between the horizontal and the initial
velocity vector of a projectile
Flame Hardening: A process of hardening a ferrous alloy by heating
it above the transformation range by means of a high-temperature flame, and then
cooling as required. (0).
Fluid: The medium used to transfer power can be a liquid or a gas.
Force: A push or pull exerted by one object on another.
Forging: The working of a piece of metal into a predetermined shape
by applying pressure or impact blows. Forging increases the strength of a part
by compressing and aligning the surface to the shape of the die.
Fracture: The act or process of breaking or the state of being
broken. (0).
Free Body Diagram: A sketch of an object (body) of interest with all
the surrounding objects stripped away and all of the
forces acting on the object (body)
shown. (0).
Frequency distribution: The number of times that a certain
characteristic occurs and is represented using a histogram.
Friction: A force that opposes the motion or intended motion of a
body in contact with another body.
Fulcrum: The support structure around which a lever rotates. See
lever.
G
Gage blocks: Accurately ground and polished blocks of steel, measured
to one millionth of an inch, and used as standards for measurements
Gear: A wheel with teeth that will allow the transfer of power when
coupled to another gear.
Gear trains: A set of gears used to transmit power, change output
direction, or change speed or force.
Gender Bias: A settled or prejudicial outlook towards males or
females.
Generator: A device that converts mechanical energy to electrical
energy.
Grains: Individual crystals in metals. (0).
Grain size: Average diameter of grains in the metal under
consideration, or alternatively, the number of grains per unit area. (0).
Graph: A diagram illustrating, by use of points, lines, line
segments or curves, the relationship between variables.
Graphics: A graphic representation (as a picture, map, or graph)
used especially for illustration.
Gravitational Potential energy: The energy stored by an object’s
position in a gravity field. On or near the surface of the Earth, PE = mgDh
where “m” is the object’s mass, “g” is the Earth’s gravitation constant, and “Dh”
is the change in height the object undergoes or has the “potential” of
undergoing.
Gravity: A fundamental physical force between any two objects in the
universe; as applied to the earth, the force that is responsible for the weight
of objects.
Ground Line: In a perspective drawing, the plane where objects
appear to rest.
H
Hardening: The process by which a piece of metal is hardened by
heating it to or above the critical temperature then cooling it rapidly, usually
by quenching in an oil or water solution.
Hard Drive: A magnetic storage device used in computer systems.
Hardness: The measure of a material's resistance to deformation by
surface indentation or by abrasion. (0).
Heat Capacity: thermal capacity, ratio of the change in heat energy
of a unit mass of a substance to the change in temperature of the substance
Heat Engine: Device that converts the energy of heat into mechanical
energy
Histogram: A bar graph that shows the frequency of events occurring
for a given range.
Hopper: A storage or supply bin that is used in a manufacturing
system.
Horizon Line: In a perspective drawing, the imaginary line at eye
level used as a construction line.
Horizontal: A line parallel to the horizon.
Hot forming: The process of working metal into shape while either in
a molten or plastic state.
Hydraulic fluid: A liquid that is used in hydraulic systems to
transfer energy; usually an oil-based substance
Hypothesis: An educated guess on the predicted outcomes of a series
of events
Hysteresis: Literally translated -Lagging behind- When a magnetic
field is created the flux lags the increase or decrease of magnetizing force.
Hysteresis results from the fact that the magnetic dipoles are not perfectly
aligned. With rapidly reversing alternating current the Hysteresis can cause a
considerable loss of energy overcoming the internal friction of the molecular
dipoles.
I
Impending Motion: Motion that is on the verge of occurring, but not
yet present.
Impact Testing: Testing used to determine a material’s ability to
withstand impact loads without fracturing.
Inclined plane – A flat sloping surface along which an object can be
pushed or pulled; a plane surface that makes an oblique angle with the plane of
the horizon. (0). One of six simple machines.
Inclusion: A foreign or impurity phase in a solid. (0).
Induction hardening: A process of
hardening a ferrous alloy by heating it above the transformation range by means
of electrical induction, and then cooling as required. (0).
Industrial Age: Age characterized by the advent of manufacturing
machinery and the movement of populations to cities from farms
Infiltration: (Thermal definition) A mechanism of heat transfer in
which cold (or hot) outside air infiltrates a heated (or cooled) building,
displacing heated (or cooled) air. This requires additional energy be expended
to heat (cool) the newly infiltrated air.
Information Age: Age characterized by the rise of Internet
communications
Initial Velocity: The velocity of an object at the beginning of the
object’s motion
Innovation: the introduction of something new; a new idea, method,
or device. (0).
Injection molding: The process of forcing a heated soft plastic into
a mold cavity where it is cooled and hardens.
Interactive: Mutual or reciprocal communication between people and/or
systems.
Interpersonal Skills: Those skills which enable an individual to work
with others in a pleasant and productive manner.
Interface: The interconnection between components or systems.
I/O: Input Output
Iron Age: The period of human culture characterized by the smelting
of iron and its use in industry beginning somewhat before 1000
B.C. in western Asia and Egypt.Bottom
of Form
Isometric: A drawing projected so that the plane of projection of a
three-dimensional drawing forms equal angles (120 degrees) to each of the three
axes of the object.
J
Job Function: Actual duties performed regardless of title.
K
K-value: A numeric expression of a material’s ability to conduct
heat energy on a unit-thickness basis.
Key: A part used to transfer torque between a shaft and a hub
Key Seat: A groove or channel cut in a shaft for the key to fit in
Kilo: a prefix meaning a thousand or 1000 or 103; symbol:
k
Kinetic Energy: The energy of an object due to its mass and motion;
calculated using the objects mass, m, and velocity, v.
Knurling: The process of impressing a diamond or straight line
pattern on a material for the purpose of improving the appearance or providing a
gripping surface.
L
LASER: Light Amplification by the Stimulated Emission of Radiation. A
device that produces a concentrated beam of light
Law of Gravitation: Governs the mutual attraction between bodies.
Where:
F=the mutual force of
attraction between the two particles
G=a universal constant
called the constant of gravitation
M1M2=
the masses of the two particles multiplied together
r=the distance between
the centers of the particles
LCL: Lower Control Limit (see definition for control limits)
LSL: Lower Specification Limit (see definition for specification
limits)
Lathe: A machine tool in which the work material is rotated around a
fixed horizontal axis and cut by a tool that is mounted on a movable carriage.
Lever: A rigid piece that transmits and modifies force or motion
when forces are applied at two points and it turns about a third; specifically:
a rigid bar used to exert a pressure or sustain a weight at one point of its
length by the application of a force at a second and turning at a third on a
fulcrum. (0).
Liability: Having a legal responsibility for the failure of a
product
Line: The path of an infinite series of points. A line has length,
but not width or thickness.
Line Graph: A diagram, or a visual representation, using a broken
line to show the relationship between certain sets of numbers.
Line Segment: A portion of a line that is defined by two points.
Line Weight: The width and darkness of a line.
Linkage: A mechanical system of related moving parts or connections.
Load: A force applied to an object (e.g. “a 30 lb load”)
Lobe: The highest point of a
cam surface
Longitudinal axis: In the Cartesian coordinate system, this would be
the “ X “ axis. Machine tools are generally designed for three axes of motion
(X, Y, Z) and an axis of rotation.
Lot: A group of products shipped or received which is supposed to
have a uniform level of quality throughout.
Lubrication: Providing a substance such as grease to reduce friction
between moving objects.
M
Magnetic: Of or relating to a magnet or to magnetism; a magnetic
material is attracted to magnets. (0).
Magnetism: A force that exists around magnets that attracts ferrous
materials and is used in motors and generators.
Malleability: The property of a material which enables it to undergo
considerable plastic deformation under compression before fracture.
Manual: An act or process done by humans.
Manual machining: Describes the operation of a machine tool by a
human operator. No computer control is involved.
Manufacturing: The total process of design, application and
production.
Martensite: A distinctive needle like structure existing in steel as
a transition stage in the transformation of austenite. It is the hardest
constituent of steel of eutectoid composition. It is produced by rapid cooling
from quenching temperature and is the chief constituent of hardened carbon tool
steels. Martensite is magnetic. (0).
Mass: The quantity of matter, which a material contains.
Mass properties: Descriptive characteristics of an object in a 3D
model.
Matrix: A chart for systematic search of possible combinations,
considering several systems’ variables at once.
Max: The largest number in a data set
Maximum Height: In the parabolic curve a projectile travels the
greatest elevation the particle obtains occurs at the horizontal coordinate of
the Range/2.
Mean: The arithmetic average of a sample of measurements.
Mean Time Between Failure (MTBF): The average time of operation
before a device is likely to fail. This is a statistical value based on testing
of representative samples of some product.
Mechanical: A form of energy, which uses motion to do work.
Mechanical Energy: The energy, which is possessed by an object due
to its motion or its stored energy of position. (0).
Mechanical fastener: A mechanical device such as a nail, screw, bolt,
and etc. that is used to fasten two parts together.
Median: The middle value in a rank order data sample. Half the values
will be greater and half the values will be less than the median.
Memory: Ability of a circuit’s output to remain at one state even
after the input condition that caused that state is removed.
Metal: An opaque lustrous elemental chemical substance that is a
good conductor of heat and electricity and, when polished, a good reflector of
light; most elemental metals are malleable, ductile, and are generally denser
than the other elemental substances; metals are structurally distinguished from
nonmetals by their atomic bonding and electron availability; the electron band
structure of metals is characterized by a partially filled valence band; the
"free electrons" lost from the outer shells of metallic atoms are available to
carry an electric current; the defining property of a metal is that it is an
element with a positive thermal coefficient of resistively, meaning the
electrical resistively of a metal continuously increases as temperature
increases. (0).
Metric system: A measuring system in which the fundamental units are
the meter, kilogram and second.
Micro: a prefix meaning a millionth or 1/1000000 or 10-6;
symbol: m, “mu”
Micrometer: A precision measuring instrument, which uses a precision
screw and a graduated scale.
Microprocessor: A complex digital chip that performs the computer
functions of arithmetic, logic and supervision.
Milli: a prefix meaning a thousandth or 1/1000 or 10-3;
symbol: m
Milling: A process of cutting or material removal, which combines a
rotating cutter and a traversing worktable allowing for processes such as
slotting, facing and pocketing.
Min: The smallest value in a data set
Mock-up: A full-sized structural model built accurately to scale
chiefly for study, testing, or display. (0).
Mode:
The number that occurs most often in a data set.
Modeling: Representation of a problem or system.
Modeling Process: The process of creating a solid, mathematical, or
other representation for the purpose of conducting a test.
Modulus of Elasticity: The slope of the line in the linear elastic
region created by the stress on the object divided by the strain
Moment: The tendency to rotate about a point determined by the
product of a force multiplied by the distance from this force to this point
Moment of inertia: An indication of the stiffness of a particular
shape. The higher the moment of inertia, the less the deflection.
Motor: A device used to convert electrical energy to mechanical
energy.
N
Necking: Reduction of the cross-sectional area of a material in a
localized area caused by uniaxial tension. (0).
Newton’s First Law: (The Law of Inertia) – Objects at rest tend to
stay at rest, and objects in motion tend to stay in motion at a constant speed
in a straight line unless acted upon by an unbalanced force.
Newton’s Second Law: The net force acting on an object in a given
direction is equal to the mass of the object multiplied by the acceleration of
the object in the same direction as the net force.
Newton’s Third Law: The force of one object (object 1) acting on
another object (object 2) is equal in magnitude and opposite in direction to the
force of the second object acting upon the first.
Nitride:
A compound of nitrogen and a metal. (0).
Non-Destructive Testing: Material or product testing in which
information is learned about the material/product via careful measurements and
recordings without destroying the material/product.
Normal distribution: A statistical curve that is bell shaped and
shows the frequency distribution for measured data. 68% of data will be
± 1 standard deviation from the mean,
95.5% of data will be ± 2 standard
deviation from the mean and 99.7% will be ±
3 standard deviation from the mean.
Normal Stress: Stress perpendicular to the area within the material
that is resisting the stress.
Nominal Group Technique: Utilizes a single, trained leader to
coordinate individual input ideas.
Non-Traditional: Unique, creative, outside the norm.
Normalizing: A heat treatment applied to steel. Involves heating
above the critical range followed by cooling in still air. Is performed to
refine the crystal structure and eliminate internal stress. (0).
Nuclear energy: Nuclear energy is the energy associated with nuclear
bonding of the nucleus of an atom. (Nuclear energy is the energy, E,
represented in the famous equation E=mc2. The mass in this equation
is not the mass of the nucleus. The mass of an atom’s nucleus is actually less
than the sum of the mass of the individual protons and neutrons within the
nucleus. The difference between these masses is known as the “mass defect,” and
is the “m” in the E=mc2. In addition, “c” is the speed of light.)
O
Object: Something visible or tangible.
Object Line: Slightly lighter than a profile line, used to add all
details to a sketch.
Oblique: A form of pictorial sketch in which two axes are at right
angles to each other (one vertical, one horizontal) and the depth axis is at an
oblique angle.
Offset method: A way of determining the yield point on a
stress-strain curve when it is not visibly identifiable.
Ohm’s Law: The relationship of voltage, current and resistance in a
circuit I=V/R, V=IR, R=V/I
Open loop: A control system where there is no feedback circuitry.
Optical: Of or relating to the science of optics or vision. (0).
Optimization: Process of making a system or design as functional or
effective as possible.
Order of Views: The relationship between the views in orthographic
projection.
Organic: Designation of any chemical compound containing carbon with
the exception of some of the simple compounds of carbon, such as carbon dioxide,
which are frequently classified as inorganic. (0).
Orthographic: Right angle projection. The views of an object are
drawn in perpendicular planes to one another.
Outside Suppliers: Vendors who provide products or services to a
company.
Out-sourcing: The process where by a company buys certain products,
subassemblies, or services from outside vendors.
Oxide: Compound of oxygen with another element. (0).
P
Parallel: Multiple pathways in a circuit
Particle: A body of negligible dimensions or when the dimensions of
a body are irrelevant to the description of its motion. E.g. an airplane wing
vs. the flight from NY to LA.
Pascal’s Law: A law that states when a force is exerted on a fluid,
the fluid transfers this force equally against the walls of the vessel.
Pattern: A regular or repeated design, form, order or arrangement.
Duplicates one or more components and arranges the resulting occurrences in a
circular or rectangular pattern.
Pearlite: Lamellar structure
resembling mother of pearl. A compound of iron and carbon occurring in steel as
a result of the transformation of austenite into aggregations of ferrite and
iron carbide. (0).
Performance: The manner in which a mechanism or part behaves.
Period: (Re: cam) the time it takes for one complete cycle of the
follower motion.
Phase: A volume of material that contains no discontinuity in either
composition or crystal structure. (0).
Photo-resistor: A device that changes resistance according to light
intensity.
Phototransistor: A semiconductor switch that produces an output when
light falls on it
Physical: Having material existence: perceptible especially through
the senses and subject to the laws of nature. (0).
Pictograph: Where symbols represent data on a graph.
Picture Plane: In a perspective drawing, it is the plane of
projection.
Pie Chart: A chart that represents data in the form of slices from a
3-D circle.
Pitch: A distance of uniform measure determined at a point on one
unit to the same corresponding point on the next unit; used in threads ,
springs, and other machine parts.
Plastics: Any of numerous organic synthetic or processed materials
that are mostly thermoplastic or thermosetting polymers of high molecular weight
and that can be made into objects. (0).
Polymer: A high-molecular-weight organic compound, natural or
synthetic, whose structure can be represented by a repeated small unit (mer).
These long molecular chains consist of repeating chemical units held together by
covalent bonds formed by a polymerization reaction. (0).
Porosity: The quality or state of being porous; the ratio of the
volume of interstices of a material to the volume of its mass. (0).
Position control: A system that uses the location of objects to
control functions.
Posture: The position or bearing of the body whether characteristic
or assumed for a special purpose.
Potential Energy: Stored energy; (Gravitational potential energy is
stored energy due to elevated position of an object: PE = mgh; Elastic potential
energy is stored energy in elastic materials: PE = ½ kx2)
Potentiometer: A variable resistor.
Power: Force over time. Measured in Ft Lbs Newton Meters or Watts
Pressure: The force generated when energy is applied to a fluid;
force per unit area
Problem solving method: Systematic efforts associated with
large-scale problems, projects, or designs.
Process control: To monitor and control a process so that the quality
of the output/product improves.
Process: The action of going through several steps to reach a desired
goal.
Processor: An electronic device that operates on data
Product: The end result of a manufacturing process or processes.
Production: The act of manufacturing a part or product
Profile Line: In sketching, a dark heavy line that outlines the
object drawn.
Projection Plane: An imaginary plane in the line of sight on which
an image appears.
Proportion: Proportion is a Principle of Design. Comparative
relationship between things with respect to size.
Programmable Logic Controller (PLC): A microprocessor used for
control engineering, primarily to replace relay logic controllers.
Programming language: A set of instructions used to operate a machine
or processor to perform a task.
Projectile Motion: The motion of objects launched in space with
negligible air resistance.
Public Welfare: Common good of society
Pulley: A wheel-like simple machine used to reduce input force,
change the direction of force applied, or to increase the input distance.
Pump: A device that converts mechanical energy to fluid energy.
Q
Qualitative: Of, relating to, or involving the measurement of
quality or kind without extensive mathematical analysis
Quality assurance: The use of quality control techniques associated
with a process.
Quality control:
The prevention of bad parts by the use of statistical techniques
Quality: The degree of customer satisfaction of a product with
respect to its use.
Quantitative: Relating to, or expressible in terms of quantity,
typically displayed in a line graph.
Quenching: In the heat-treating of metals, the step of cooling
metals rapidly in order to obtain desired properties; most commonly accomplished
by immersing the metal in oil or water. In the case of most copper base alloys,
quenching has no effect other than to hasten cooling. (0).
R
: Range, Indicates amount of variation that exist in the machine process
R-Value: A numeric expression of thermal insulation. R-values are
the reciprocals of U-values.
Racial Bias: A settled or prejudicial outlook toward various races
Radiation: (Thermal definition) Transfer of heat by temporarily
transforming the heat (kinetic motion of an objects atoms or molecules) into
electromagnetic waves (in the infrared part of the EM spectrum). These waves
then travel until absorbed by another object and transferred back into
atomic/molecular kinetic energy, which is heat.
Ram: Random Access Memory
Range: a) The horizontal distance traveled by a projectile. b) The
difference between the largest and smallest piece of numerical data.
Ratchet: a mechanism that consists of a bar or wheel having inclined
teeth into which a pawl drops so that motion can be imparted to the wheel or
bar, governed, or prevented and that is used in a hand tool (as a wrench or
screwdriver) to allow effective motion in one direction only
Reaction: Reactions are passive forces that are induced at the
supports of a structure
Receiver:
A device that accepts signals from the emitter
and is used in control systems.
Reciprocating: Motion back and forth along a linear path.
Rectification: The process of converting AC into DC
Redundant: An additional part or subsystem that is added to a system
to increase the overall system reliability. Redundant components serve their
function in parallel; as long as any one redundant component is functional, the
entire system still functions as designed.
Relay: Electromechanical switch where contacts are opened or closed
by a control circuit in order to switch a secondary circuit
Reliability: The probability of satisfactory operation of the product
in a given environment over a specified time interval
Research: Careful or diligent search; studious inquiry or
examination; especially : investigation or experimentation aimed
at the discovery and interpretation of facts, revision of accepted theories or
laws in the light of new facts, or practical application of such new or revised
theories or laws; the collecting of information about a particular subject.
(0).
Resilience: The tendency of a material to return to its original
shape after the removal of a stress that has produced elastic strain. (0).
Resistance: The ratio of the potential difference across an
electrical component to the current passing through it. It is thus a measure of
the component's opposition to the flow of electric charge. In general, the
resistance of a metallic conductor increases with temperature whereas the
resistance of a semiconductor decreases with temperature. (0).
Resistor: A component used for introducing resistance into a circuit
Resume: A document which briefly summarizes who you are; it contains
your education, work experience, accomplishments, and other necessary personal
information.
Rise: The segment of cam rotation that causes the follower to move
upward
Rivet: Mechanical fastener with a large head used for joining two
parts together through a hole. The rivet is clinched by forming a second head
on the opposite side.
Robotics: The specialized field of engineering and computer science
that deals with the design and application of robots.
Role Model: A person whose behavior in a particular role is imitated
by others.
Rolling: A process in which a heated or cold material is passed
between rollers, squeezing it into various shapes and thickness. Some
applications include rods, bars, sheet, plates and foils.
Rom: Read Only Memory
Rotation: Clockwise or counterclockwise spin of an object about its
own axis.
Rupture Strength: The stress at which a material ruptures.
S
Sample: A portion of the product randomly taken for testing so
decisions can be made about the whole.
Scale: A graduated series of numbers used for measurement purposes.
Scale: The ability to change the proportions or size of one part of
the image in relationship to the other.
Scalar Quantity: A quantity that can be described by magnitude only;
answers the question “how much?” Examples: mass, time.
Screw: A simple machine that uses threads to apply force; a spiral
inclined plane surrounding a center shaft.
Seals: A device to prevent the passage or return of gas, liquid or
air into a pipe or container, a tight and perfect closure
Semiconductor: Materials whose electrical conductivity can be
precisely altered by appropriate manufacturing processes.
Separating: The process by which a material is divided into two or
more parts.
Series: A circuit with only one pathway for electrons
Shafts: Cylindrical rods that support pulleys, gears, and sprockets
to transmit torque.
Shape: The physical geometry of a model.
Shear: Force that acts parallel to the surface of the material
Shearing: The process of separating a material by applying pressure
from opposing directions; the area of separation is parallel to the force
applied
SI: (System International) see metric system
Sigma: Greek letter that is associated with the standard deviation in
statistics and stress in strengths of materials;
s
Simple Machine: Any one of the mechanisms which were once considered
to be the basic elements from which all machines were composed. These include
the lever, the wheel and axle, the pulley, the inclined plane, the wedge and the
screw.
Sketch: A freehand drawing of an idea, or solution to a problem
without concern for detail.
Slope: An incline or decline mathematically calculated as the rise
divided by the run.
Soldering: The joining of metal surfaces with a different metal
(solder) that melts at a temperature below the red heat temperature of iron.
Solenoid: An electromagnetic device that converts electrical energy
into linear motion.
Solid modeling: Three-dimensional CAD representation used to
describe, simulate and predict the behavior of objects.
Solution: A satisfactory or possibly satisfactory answer to a
problem.
Space Age: Relating to, or befitting the age of space exploration
Spatial Configuration: The relative arrangement of parts or elements
within three-dimensional space.
Specification Limits: (Lower and upper specification limits (LSL
and
USL)); these are the actual limits that are usually set based on customer
needs.
Spinning: The procedure of making sheet metal discs into hollow
shapes by pressing the metal against a rotating form (spinning chuck) by a tool.
(0).
Spline: One of a series of keyways cut around a shaft and mating
hole, used to transfer power from a shaft to a hub while allowing a sliding
action between the parts
Specific Gravity: The ratio of the density of a substance to the
density of some substance (as pure water) taken as a standard when both
densities are obtained by weighing in air. (0).
Spread: The distribution of data within a statistical sample.
Spreadsheet: Software packages designed to simplify the manipulation
and presentation of numbers and text; spreadsheets allow the user to change
parameters of the calculation and see the effect on all calculations; also, most
spreadsheets have powerful presentation software, such as graphs, bar charts,
etc.
Spring: A mechanical device that stores energy by expansion or
contraction due to pressure, force or stress applied, that will release energy
and return to shape when the force or stress is removed.
Sprocket: A circular mechanical device with teeth that is used to
impart motion to chains.
Standard deviation: A mathematical measure of the spread in a data
sample. Symbol: s, “sigma”
Standards: Benchmarks used to measure or combine results.
Statics: The study of objects in a state of equilibrium.
Station Point: The point where the viewer stands to observe the
image on the picture plane.
Statistics: 1) a branch of mathematics dealing with the collection,
analysis, interpolation and presentation of masses of numerical data; 2) a
collection of quantitative data.
Statistical Process Control:
SPC is a method of monitoring,
controlling and, ideally, improving a process through statistical analysis. Its
four basic steps include measuring the process, eliminating variances in the
process to make it consistent, monitoring the process, and improving the process
to its best target value
Stereotyping: Something conforming to a fixed or general pattern.
Stone Age: The first known period of prehistoric human culture
characterized by the use of stone tools.
Strain: The elongation of a material under stress divided by the
material’s length prior to stress; symbol: e,
“epsilon”
Stress: A material’s internal resistance to force; symbol:
s, “sigma”; calculated by dividing the
force in the material by the area of the material that is subjected to the
force:
Stress-Strain Curve: A graph of stress (on the y-axis) versus strain
(on the x-axis) for materials under stress; enables engineers to learn about the
strength of material as it deforms elastically and plastically.
Stud: Vertical Structural member
Surface: A two-dimensional area on a plane.
Suspension Bridge: “a bridge having a road or deck hung from a pair
of steel cables, each carried by two towers, one at each bank; e.g., the Golden
Gate Bridge over San Francisco Bay”
Switch: Device used to control the flow of current in a circuit.
Synchronous: An AC electric motor whose speed is dependent upon the
frequency of the input current.
Synetics: A group interaction, utilizing seemingly unrelated ideas,
to bring about one or two solutions.
Synthesis: The process of forming, generating or putting together
ideas or parts to form a whole.
Synthetic: Not naturally occurring, manufactured.
Systematic: Marked by thoroughness and regularity, also methodical
in procedure or plan
T
Table: A table is made up of rows and columns of cells that you can
fill with text and graphics. Tables are often used to organize and present
information.
Tank: A usually large receptacle for holding, transporting, or
storing liquids. (0).
Tapping: The process of cutting an internal thread using a tap.
Technical writing: Treating a document with the goal of providing
clear and concise information, rather than entertainment or story telling; a
technical document/report incorporates diagrams and multi-media information to
provide technical information.
Temple Stick: A temperature-sensing device that looks like a crayon
and only melts when applied to the surface of a material heated to a specific,
predetermined temperature.
Temperature: A measurement of how warm something is; also the average
kinetic energy of the individual molecules of a substance
Tempering: A heat treating process that reduces the brittleness of a
hardened piece of steel by heating it to a point below the critical temperature
and cooling it at some rate.
Tension: A situation in which force is applied to an object that
stretches, expands or lengthens the object.
Tensile: Of or relating to tension; a “tensile” force is a force
that serves to stretch, expand, or lengthen an object.
Thermal: of, relating to, or caused by heat. (0).
Thermal energy: Thermal energy is basically kinetic energy. It is
the sum of the individual atoms’ kinetic energies. Even in a completely
motionless object, the atoms from which the object is made are in constant
motion and thus have thermal energy.
Thermodynamics: The study of thermal energy as it moves from one
substance to another.
Thermoplastic: A material capable of being repeatedly softened by
increases in temperature and hardened by decreases in temperature.
Thermoplastics are those materials whose change upon heating is substantially
physical rather than chemical. They are largely one- or two-dimensional
molecular structures such as: nylons, polycarbonates, acetals, polysulfones, and
vinyls. (0).
Thermoset: A material, such as an epoxy or polyester resin, which
has the property of undergoing a chemical reaction by the action of heat,
catalyst, ultraviolet light, etc., to become a relatively insoluble and
infusible substance. They develop a well-bonded three-dimensional structure upon
curing. Once hardened or cross-linked, they will decompose rather than melt.
(0).
Theory: A plausible or scientifically acceptable general principle
or body of principles offered to explain phenomena; (scientifically quite
different from a “hunch”) (0).
Thread: A spiral groove cut into the outside of a shaft or the
inside of a hole used to hold parts together.
Threading: The process of cutting spiral mating surfaces for the
purpose of providing mechanical tension between two parts. (The process of
using a tap or die)
Time Line: A table listing important events for successive years
within a particular historical period.
Timetable: Estimated timeline for completion of a process.
Tolerance: The difference between the maximum and minimum dimensions
allowed within the design of a product.
Torque: A turning or twisting force that produces or tends to
produce rotation or torsion
Torsion: The twisting or wrenching of a body by the exertion of
forces tending to turn one end or part about a longitudinal axis while the other
is held fast or turned in the opposite direction. (0).
Toughness: The energy required to break a material, which is equal
to the area under the stress-strain curve. The toughest materials are those with
very great elongations to break accompanied by high tensile strengths such
materials nearly always have yield points. (0).
Traditional: Standard or established practice.
Transducer: A device used to inform various control systems.
Transformation: A constitutional change in a solid metal, e.g., the
change from gamma to alpha iron, or the formation of pearlite from austenite.
(0).
Transverse axis: In the Cartesian coordinate system, this would be
the “ Z “ axis. Machine tools are generally designed for the axis of motion (X,
Y, Z) and a axis of rotation.
Triple beam balance: Equipment to measure mass using gravitational
pull.
Turning: Using a lathe.
U
U-Value: A numeric expression of a material’s thermal conductivity;
the degree that heat energy can pass through a material.
UCL: Upper Control Limit (see definition for control limits)
USL: Upper Specification Limit (see definition for specification
limits)
Ultimate Strength: The maximum stress a material withstands prior to
necking.
V
Valve: Any of numerous mechanical devices by which the flow of
liquid, gas, or loose material in bulk may be started, stopped, or regulated by
a movable part that opens, shuts, or partially obstructs one or more ports or
passageways. (0).
Vanishing Point: The point on the horizon where parallel objects
appear to intersect due to convergence.
Variation: Differences that exist in any manufacturing process.
Abnormal variations need to be removed; random or normal variations cannot be
removed.
Vernier caliper: Instrument to precisely measure inside and outside
diameters.
Vernier Scale: A physical scale that is used on a variety of
measurement tools that allows the user to measure to one ten thousandths of an
inch.
Vector Quantity: A quantity that must be described by both magnitude
and direction; answers the questions “how much?” and “which way?” Examples:
velocity, Force.
Velocity: The ratio of the displacement of a particle and the time
interval
Vertical axis: In the Cartesian coordinate system, this would be the
“ Y “ axis. Machine tools are generally designed for three axes of motion
(X,Y,Z) and an axis of rotation.
Vertical: Perpendicular to the horizon.
Viscosity: The thickness or flow characteristic of a liquid; the more
viscous, the slower a liquid will flow.
Views: The different viewing perspectives found in mechanical
drawing.
Visual Aids: Instructional devices (as a chart, map, or model) that
appeals chiefly to vision use to convey difficult concepts.
Visualization: To form a mental image of something.
Vita: A document which briefly summarizes who you are; it contains
your education, work experience, accomplishments, and other necessary personal
information.
Voltage: The electromotive force in a circuit.
Volume: The amount of space occupied by a three-dimensional object as
measured in cubic units.
W
Water jet: A separating process that uses a high-velocity stream of
water as the cutting agent. (abrasive material is sometimes used in the water)
Watt’s Law: The mathematical relationship expressing that power is
the product of Voltage and Current
Wedge: A simple machine used to change the direction of applied
force via its triangular shape; used for splitting wood and rocks, raising heavy
bodies, or for tightening by being driven into something.
Welding: The process of joining metal together by heating to the
fusion point
Weight: The gravitational pull (force) on an object.
Wheel and Axle: a. A simple machine in which a larger diameter
wheel requires less force to turn than a smaller diameter axle (e.g. valve
handles, steering wheel); b. A simple machine that turns rotary motion into
linear motion whereby increasing the diameter of the wheel, the linear distance
traveled for one revolution of the axle can be increased; c. a rotating lever
Whistle Blowing: Public disclosure of a moral or ethical problem.
Work: Done by a force acting on an object when the point of
application of that force moves through some distance and the force has a
component along the line of motion
Working Circle: A circle in a displacement diagram that has a radius
equal to the distance from the center of the cam to the highest point on the
cam.
Working Relationship: A mutually satisfying and productive ongoing
interaction.
: X-bar, Average or level at which a machine
or process is operating
Sources: