Materials Flashcards
load or force passing through the axis of rotation
radial load
the number of revolutions or hours at a given constant speed that 90 percent of an apparently identical group of bearings will complete or exceed before the first evidence of fatigue develops
rated life
the radial load that a ball bearing can withstand for one million revolutions of the inner ring
basic dynamic load
rating
constant stationary radial load which, if applied to a bearing with rotating inner ring and
stationary outer ring, would give the same life as that which the bearing will attain under the
actual conditions of load and rotation
equivalent dynamic
load
the maximum radial load, which corresponds to a calculated contact stress at the center of
the most heavily, loaded rolling element/raceway contact
basic static load
rating
static radial load, if applied, which produces a maximum contact stress equal in magnitude to the maximum contact stress in the actual condition of loading
equivalent static load
a mechanical device designed specifically to hold, join, or maintain equilibrium of single or multiple components
fastener
an externally threaded fastener designed for insertion through holes in assembled parts, and
normally tightened or released by torquing a nut
bolt
a block or sleeve having an internal thread designed to assemble with the external thread on a bolt, screw, stud or other threaded part
nut
the designation used for the purpose of general identification
nominal size
the distance from the intersection of the largest diameter of the head with the bearing surface to the extreme end of the fastener, measured parallel to the axis of the fastener
length of fastener
thread which winds in a clockwise and receding direction from the starting end, when viewed from that end
right hand thread
a thread which winds in a counterclockwise and receding direction from the starting end,
when viewed from that end
left hand thread
the specified load which the fastener must withstand without any indication of permanent deformation after the load is released
proof load
the distance (in millimeters), measured parallel to the thread axis, between corresponding
points on adjacent thread forms in the same axial plane on the same side of the axis
pitch
for a straight thread, this is the diameter of the imaginary cylinder bounding the crest of an external thread or the root of an internal thread
major diamater
for a straight thread, this diameter is the imaginary cylinder bounding the root of an external thread or the crest of an internal thread
minor diameter
for a straight thread, this is the diameter of the imaginary cylinder whose surface passes
through the thread profiles in such a way to make the widths of the thread ridge and the
thread groove equal
pitch diameter
used to join lengths of shafting, which must often be sectionalized for practicability and economy in manufacture and shipping or for purposes of ready installation
couplings
couplings which permits the disengagement of the coupled shafts during rotation
clutches
used for the transmission of power from a shaft to hub or vice versa.
splines
designed to reduce coupling shack by slipping during the engagement period. They also
serve as safety devices by slipping when the torque exceeds their maximum rating.
friction clutch
produces its torque by virtue of the centrifugal force of weights pressing against the driving
or frictionally driven member.
centrifugal clutch
consists of a frustum of a cone, so fitted to a shaft by means of a feather key that it can be
pushed into an opposite engaging surface rigidly attached to the other shaft
conical friction clutch
designed to transmit torque without slip, jaw clutches are the most common
positive clutch
used when the shafts are virtually collinear and when they remain in a fixed angular relation with respect to each other (except for angular deflection).
rigid coupling
essentially a split and bolted sleeve coupling, proportioned to clamp firmly on the shafts
clamp shaft coupling
commonly used in permanent installations for heavy loads and large sizes and particularly
for vertical drives, as agitators
flange face coupling
designed to connect shafts which are misaligned either laterally or angularly. A secondary benefit is the absorption of impacts due to fluctuations in shaft torque or angular speed.
flexible coupling
used to connect shafts with much larger values of misalignment than can be tolerated by the
other types of flexible couplings
universal joint
multiple keys in the general form of internal and external gear teeth, used to prevent
relative rotation of cylindrically fitted machine parts
involute splines
are employed in multiple-spline fittings having 4, 6, 10, or 16 splines
square splines
synthetic organic material, including cellulose derivatives, with or without the incorporation of fillers, binders, pigments, dyes, which is capable of being shaped
plastics
simple unpolymerized form of chemical compound
monomer
chemical compound with higher molecular weight consisting of a number of structural units linked together by covalent bonds
polymer
polymers consisting of more than one monomer
copolymer
non-ionic chemical bond formed by stored electrons
covalent
substances that melt on heating and are processes in this state by a variety of extrusion and
molding process
thermoplastic
substances that cannot be melted and remelted
thermoset
temperature at which the plastic can withstand without incurring a change in its physical properties
service temperature
belts used to transmit rotary motion and power between two shafts, which lie flat on the
face of its corresponding pulley
flat belt
wheel having flat or crowned face used to transmit motion and power by means of flat belts
flat belt pulley
power transmission device used to transmit power and motion between two shafts
consisting of flat belts which ride in flat pulleys
flat belt drive
outside diameter of the pulley
pulley diameter
stretched-out length of the belt
belt length
ratio of the angular velocities of the pulleys making no allowance for slip and creep
speed ratio
the linear speed of the belt calculated by multiplying the rpm and the diameter of the driver pulley and to the value of pi
belt speed
cylindrical gear whose tooth traces are helices, it transmits rotational motion and power
between two parallel axes
helical gear
each of the projecting parts of a gear which is intended to ensure, by contact with the teeth of another gear, that one gear turns the other
gear tooth
quotient of the circular pitch, expressed in millimeters, to the number π (or the quotient of
the diametral pitch, expressed in millimeters, to the number of teeth)
module
quotient of the normal circular pitch (expressed in millimeters) and the number π, where the normal circular pitch is the product of the circular pitch and the cosine of the helix angle
normal module
line of intersection of the pitch cylinder by a plane perpendicular to the axis of the gear
pitch circle
radial distance between the addendum circle and the pitch circle
addendum
circle that bounds the outer ends of the teeth
addendum circle
radial distance between the dedendum circle and the pitch circle
dedendum
line of intersection of the dedendum cylinder by a plane perpendicular to the axis of the
gear
dedendum circle
amount by which the dedendum in a given gear exceeds the addendum of its meshing gear
clearance
diameter of the pitch circle*
pitch diameter
diameter of the addendum circle
addendum diameter
diameter of the of the dedendum circle
dedendum diameter
radial distance between the addendum circle and the dedendum circle
tooth depth
length of the arc of the pitch circle between two consecutive corresponding points of
adjacent teeth
circular pitch
length of the arc, living between the tooth traces of two consecutive corresponding flanks of a cylindrical normal helix
normal circular pitch
width of the tooth measured along the circular pitch
tooth thickness
space between teeth measured along the pitch circle
tooth space
difference between the tooth space and the tooth thickness
backlash
width over the toothed part of a gear, measured along a straight line generator of the
reference cylinder
face width
portion of the surface of a tooth lying between the tip surface and the root surface
tooth flank
pressure angle at the point where the profile cuts the pitch circle
pressure angle
pressure angle at a point on a tooth trace
normal pressure
angle
curve whose tangents are inclined at a constant angle to the axis of the cylinder
helix
in a cylinder on which helix is considered, a helix which is perpendicular to that helix
normal helix
acute angle between the tooth trace and the generator of any imaginary cylinder or cone
coaxial with a gear whose tooth trace is under consideration
helix angle
the line of intersection of a tooth flank with any defined surface cutting the reference
surface
tooth profile
the line of intersection of a flank with the reference surface
tooth trace
a cylindrical gear of which every usable tooth profile is an arc of an involute to a circle
involute cylindrical
gear
plane curve described by a point on a straight line (the “generating line”), which rolls out without slip on the base circl
involute to a circle
sleeve bearing; a cylinder which surrounds the shaft and is filled with some form of fluid
lubricant
journal bearing
the part of the rotating shaft , axle, roll or spindle that turns in a bearing
journal
a medium that supports the shaft preventing metal to metal contact
lubricant
keys whose longitudinal sides are parallel with each other
parallel keys
keys with a tapered longitudinal section
taper keys
keys with a semi-circular cross-section
woodruff keys
long evenly shaped piece of solid metal
bar
steel bar with lugs or protrusions called deformations
deformed bar
diameter equivalent to the diameter of a plain round bar having the same mass per meter
nominal diameter of
deformed bar
long hollow cylinder of specified thickness whose nominal size is approximated by the inside
diameter
pipe
long hollow product of round or any other cross-section whose size is specified by the
outside dimensions
tube
rolled rectangular section of thickness over 0.15 mm up to 6.0 mm, with sheared, slit or
sawn edges
aluminum and
aluminum alloy sheet
galvanized flat or corrugated metal product cut to the standard or specified length and has a nominal base metal thickness ranging from 0.20 mm to 1.6 mm and a flat width of 760 mm to 1,220 mm
galvanized steel sheet
quotient of the load (when the specified permanent elongation occurs in a tensile test)
divided by the original cross-sectional area
proof stress
term applied to changes in physical and mechanical properties of low carbon steel that occur with the passage of time and adversely affect formability
ageing
removal of oxygen which causes oxidation of steel
deoxidation
a headed pin of metal used for uniting two or more pieces by passing the shank through a
hole in each piece and then by beating or pressing down the plain end so as to make a
second head
rivet
the diameter of the shank
nominal diameter
a type of riveted joint wherein the plates overlap each other and are held together by one or
more rows of rivets.
lap joint
a type of riveted joint wherein the plates being joined are in the same plane and are joined
by means of a cover plate or butt strap which is riveted to both plates by one or more rows of rivets
butt joint
spacing between rivet centers
pitch
the distance from the edge of the plate to the centerline of the nearest row of rivets
margin
allowance in length of rivet in order to turn over or flatten the protruding end
clinch allowance
distance between adjacent joint members
chain pitch
the diameter of a circle tangent to the curve (called the seating curve) at the bottom of the
tooth gap
bottom diameter
for a sprocket with an odd number of teeth, it is the distance from the bottom of the tooth gap to that of the nearest opposite tooth gap
caliper diameter
it is the diameter over the tips of the teeth
outside diameter
an externally threaded fastener capable of being inserted into holes in assembled parts, of
mating with preformed internal thread or forming its own thread, and of being tightened or released by torquing the head
screw
Used to increase the bearing area thus distributing the fastener load over a large area,
particularly on soft materials such as aluminum.
hexagonal flange
head
For applications where space is restricted making impossible to use a wrench for tightening.
pan head
When space is restricted making impossible to use a wrench for tightening, and where a flat surface is required.
flat countersunk head
When space is restricted making impossible to use a wrench for tightening, where a flat surface is required. This type shall be recommended for machine parts that are always
disassembled.
oval countersunk
head
When space is restricted making impossible to use a wrench for tightening and for
applications that requires no protruding parts of the machine.
slotted head
For applications that require no protruding parts of the machine. The use of this type of
setscrew allows easy assembly and disassembly of machine parts
hexagon socket head
a cylindrical gear whose tooth traces are straight lines parallel to the axis. Generally, it
transmits rotational motion and power between two axes
spur gear
each of the projecting parts of a gear which are intended to ensure, by contact with the
teeth of another gear, that one of the other gear turns the other
gear tooth
used to transmit power between shafts at practically any angle
bevel gear
bevel gears whose teeth are straight but the sides are tapered so that they would intersect the axis at a common point called the pitch cone apex if extended inward
straight bevel gears
bevel gears having equal numbers of driver and driven gear teeth and operate at axes with right angles
miter gears
the portion of the bevel gear tooth near the inner end
toe
the portion of the bevel gear tooth near the outer end
heel
the angle between an element of the front cone and a plane of rotation
front angle
the angle between an element of the face cone and its axis
face angle
the angle between meshing bevel gear axes: also, the sum of the two pitch angles
shaft angle
the angle formed between a tooth element and the axis of the bevel gear
root angle
the distance along the axis from apex of pitch cone to a locating registering surface on back
pitch apex to back
the distance from the crown to the rear of the gear
crown to back
the sharp corner forming the outside diameter
crown
the diameter and/or plane of rotation surface which is used in locating the gear in the
application assembly
mounting surface
for assembled bevel gears, the distance from the crossing point of the axes to the registering surface, measured along the gear axis; ideally it should be identical to the apex to back
mounting distance
the distance along an element of the back cone from the apex to the pitch circle
back cone distance
the angle of a cone whose elements are tangent to a sphere containing a trace of the pitch circle
back cone
the angle between an element of the back cone and the plane of rotation
back angle
the distance from the end of the tooth to the pitch apex
cone distance
the angle formed between an element of the pitch cone and the bevel gear axis, it is the half
angle of the pitch cone
pitch angle
high density fiberboard that has been specially treated with drying oil, petroleum derivatives or other compounds stabilized by baking or heating, and generally intended for the use where moisture resistance is required.
tempered fiberboard
A high density fiberboard without subsequent treatment generally intended for interior use
standard fiberboard
A hardboard without any factory-applied finish.
plain
High density fiberboard with a smooth surface on one side and a screen impression on the
other side.
smooth one side
flexible machine element used to transmit motion and power between two shafts, the cross
section of which is shaped roughly like a regular trapezoid outlined by the base, sides and
top of the belt
v belt
wheel with one or more grooved rims used to transmit motion and power by means of one or more V-belts
v pulley
power transmission device, which consists of one or more V-belts, mounted on two or more V-pulleys
v belt drive
type of plywood intended for outdoor or marine uses, also known as Type I
exterior plywood
surface of the plywood showing veneer of higher grade than that of the back side
face
plywood faced with a material other than wood, such as metal or plastic
face plywood
panel made of consolidated ligno-cellulosic fibers with the primary bond derived from their inherent adhesive properties and/or the addition of resin or other materials
fiberboard
consist essentially of an inorganic hydraulic binder or a calcium silicate binder formed by the chemical reaction of a siliceous material and a calcareous material reinforced by organic fibers and/or inorganic synthetic fibers
fiber cement flat
sheets
type of plywood intended for inside use, having limited moisture resistance
interior plywood
side board made up of well machined lumber strips properly dried and glued together
lumber core
ply board; plywood made up of face/back veneer, crossboard core veneer and well composed kiln dried lumber core
lumber core plywood
sheet of plywood
panel
board principally made from wood chips and formed by hot press process with adhesive
particle board
stratum or layer used in referring to the successive layers of veneer in a panel
ply
assembled product made of layers of veneers and/or lumber core held together by an adhesive, the chief characteristics of which is the alternate cross layers, distributing the longitudinal wood strength
plywood
Hardboard which has a pattern impressed on one surface, e.g. simulating some other materials such as leather, sawali, wood grain, bark, diamond, fine weave, and others
decorative
Usually S1S hardboard with holes punched or drilled at the factory for use with various
fixtures to provide decorative wall-mounted storage facilities or which may be used for
acoustic purposes.
perforated
High density fiberboard with smooth surfaces on both sides.
smooth two sides
This bonding class is appropriate for veneer plywood intended for use in normal interior climates.
class 1 dry conditions
This bonding class is appropriate for veneer plywood intended for protected external
applications (e.g. behind cladding or under roof coverings), but capable of resisting weather
exposure for short periods (e.g. when exposed during construction).
class 2 humid conditions
This bonding class is designed for veneer plywood intended for exposure to weather over
sustained periods.
class 3 exterior conditions
This provides high strength and stiffness while offering enhanced dimensional stability and ease of machining. A semi-crystalline material, with low coefficient of friction
and good wear properties-especially in wet environments.
acetals
one of the most versatile and widely used thermoplastic materials. Its physical properties and reasonable price combine to make it a popular choice for numerous applications.
polyamide
Engineering plastic which can replace steel, brass, bronze, aluminum, wood, and rubber,
while reducing noise, using less lubrication, and increasing gear life.
polyamide
an amorphous thermoplastic with excellent dimensional stability and good strength and
stiffness over a wide range of service temperatures. It is often used for structural applications when transparency and impact strength are essential
polycarbonate
suits a wide variety of electrical applications as well, because of its low moisture absorption,
good insulation and excellent flammability rating.
polycarbonate
It is an inexpensive alternative to metals, ceramics, and wood because it is self-lubricating;
long-wearing; and shatter-, abrasion-, and corrosion-resistant.
polyethylene umhwpe
noted for its light weight, being less dense than water; it is a polymer of propylene. It resists
moisture, oils, and solvents
polypropylene
It is more popularly known as Teflon, and is based on chain of carbon atoms, the same as all
polymers.
polytetrafluoroethylene
a thermoplastic that is a polymer of vinyl chloride.This plastic has found extensive use as an electrical insulator for wires and cables.
polyvinyl chloride
It can be machined or cemented and, with standard equipment, will fabricate like wood, metal, or other plastics. It weighs half as much as comparable glass and yet has good shatter resistance and durability.
acrylic
Pin used as locking device for other fasteners. Used with a slotted nut on bolt, screws, or
studs, it provides a convenient, low-cost locknut assembly.
split
Pin used for light-duty service in the attachment of wheels, levers and similar components
to shafts
taper
Pin holding laminated sections together with surfaces either drawn up tight or separated in
some fixed relationship.
parallel or dowel
Pin for fastening machine parts where accuracy of alignment is a primary consideration.
parallel or dowel
Pin for locking components on shafts
parallel or dowel
Pin used in connecting mating yoke, or fork, and eye members in knuckle-joint assemblies
clevis
This bearing is often referred to as the deep groove or conrad bearing
single row radial
Bearing which is available in many variations such as single, double shields, and seals.
single row radial
This type of bearing is normally used for radial; and thrust loads (maximum two-thirds of
radial).
single row radial
bearings which have a geometry that is similar to that of a deep-groove bearing except for a filling slot
maximum capacity
bearing
This bearing provides for heavy radial and light thrust loads without increasing the outside
diameter of the bearing. It is about 60 to 80 percent wider than a comparable single-row
bearing. Because of the filling slot, thrust loads may be light
double row
This bearing may be used for primarily radial loads where self-alignment (±4°) is required.
The self-aligning feature should not be abused, as excessive misalignment or thrust load (10
percent of radial) causes early failure.
internal self-aligning
double-row
These bearings are designed to support combined radial and thrust loads or heavy thrust
loads depending on the contact-angle magnitude
angular contact bearing
This type of bearing is used for linear motions on hardened shafts (Rockwell C 58 to 64).
Some types can be used for linear and rotary motions
ball bushings
This type of ball or roller bearing has split inner, outer ring, and cage, which are assembled by screws. This feature is expensive but useful where it is difficult to install or remove a solid bearing.
split type ball bearing
Bearings which may be used for low-speed applications where other bearings carry the
radial load. These bearings are made with shields, as well as the open type.
ball thrust bearing
These bearings utilize cylinders with approximate length/diameter ratio ranging from 1:1 to 1:3 as rolling elements.
cylindrical roller
Bearings which are normally used for heavy radial loads and especially useful for free axial
movement of the shaft. They also have the highest speed limits for roller bearings.
cylindrical roller
These bearings have rollers whose length is at least 4 times their diameter. They are the
most useful where space is a factor and are available with or without inner race, it must be
hardened or ground.
needle bearing
Type of needle bearing which is used for high loads, oscillating, or slow speeds.
full-complement type
Type of needle bearing which should be used for rotational motion. They cannot support
thrust loads.
cage type
These bearings are used for heavy radial and thrust loads. They are designed so that all
elements in the rolling surface and the raceways intersect at a common point on the axis:
thus true rolling is obtained.
tapered roller
These bearings are excellent for heavy radial loads and moderate thrust.
spherical roller
These bearings are made of a series of short rollers to minimize the skidding, which causes twisting of the rollers. They may be used for moderate speeds and loads.
straight-roller thrust
bearing
It eliminates the skidding that takes place with straight rollers but causes a thrust load
between the ends of the rollers and the shoulder on the race. Thus speeds are limited
because the roller end and race flange are in sliding contact.
tapered-roller thrust
bearing
Washer used to produce a predetermined pressure on adjacent members where sliding action is desired, or to serve as spring take-up devices in an assembly.
spring lock washer
Washer used with screws to add spring take-up to screw elongation.
conical spring washer
Toothed lock washer used when projection of teeth beyond the head or nut is
objectionable.
internal toothed
Toothed lock washer used when security of assembly is critical.
external toothed
Toothed lock washer used under countersunk screw heads.
countersunk external
toothed
Tooth locked washer used against soft materials and thin steel sheet
internal external toothed
Washer which provides bearing surface for a nut or screw head, covers large clearance
holes, and distribute fastener loads over large area, particularly on soft materials such as aluminum or wood.
plain washer
Washer used with screws and nuts not only to effectively add spring take-up to the screw
elongation but to increase the frictional resistance under the screw hard or nut face.
toothed lock washer
