Abrasive
A substance used for
abrading – grinding – polishing – lapping, such as the natural
materials Emery, Garnet, Flint, and Crocus, and the manufactured or
electric furnace materials Aluminum Oxide, Silicon Carbide, and
Zirconia Alumina. One of the three essential components of a coated
abrasive product (backing, adhesive, abrasive grain).
Abrasive Machining
Rough grinding metal
parts to a desired size (roughing and shaping), and finishing them
to required tolerance and surface finish (dimensioning and
finishing) using coated abrasive belts.
Abrasive Planing
Glued –up or lumber
banded man-made board panels prior to intermediate sanding or the
application of overlays.
Accuracy
Conformity in dimension
to an exact standard.
Active Filler
A fine, solid material
dispersed in the grain bond adhesive of a coated abrasive, which is
chemically reactive during grinding to promote faster and/or
smoother cutting action by the coated abrasive product. These
materials are useful primarily in grinding stainless steels, other
high nickel alloys, and titanium.
Adhesive
The substance used to
bond the grain to the backing on a coated abrasive product.
Alumina
Unfused aluminum oxide.
Aluminum Oxide
An abrasive made by
fusing the mineral bauxite.
Anneal
To treat a metal, alloy,
or glass with heat and then cooling, thereby removing internal
stresses and making the material less brittle.
Arbor
The spindle of the
grinding machine on which the contact wheel or idler pulley is
mounted.
Arbor Hole
The hole in the contact
wheel or idler pulley sized to fit the machine arbor.
Arc of Contact
That portion of the
circumference of the coated abrasive belt touching the work being
ground, when on a contact wheel.
Area of Contact
The total area of the
grinding surface of a coated abrasive product in contact with the
work being ground.
Arithmetic Mean
The average of a
collection of numbers obtained by dividing the sum of the numbers by
the quantity of the numbers. Also known as average.
Assemblies
A term used to describe
a section of abrasive used in the loading of a Vonnegut Head Brush
Sander. Available with the pieces either straight scored, staggered
scored, or unscored, these cloth specialties are used for fine
sanding of contoured wood parts when finishing is required without
destroying character lines.
Automatic Tracking
A system that ensures
the coated abrasive belt runs true on a contact roll or idler. These
automatic tracking systems are usually tight of all controllers and
constantly adjust belts during operation to achieve ideal and
consistent tracking.
Backing
A flexible or semi-rigid
material to which abrasive grain is bonded by an adhesive. Paper,
cloth, fibre and combination are the major backings used for coated
abrasives.
Back Pass
A light grinding cut
taken on the bottom (back) side of coil or sheet material, to
relieve stresses from rolling and to prevent distortion from
occurring during subsequent grinding operations on the finish side.
Back Satin
Smoothing the print side
of coated abrasive backings to retard platen wear during use. The
process is employed primarily for wide and narrow belt applications
involving fine and coarse grit polyester products.
Backstand
One of the most popular
industrial abrasive belt machines for offhand or other grinding and
finishing. Preferably floor-mounted, it usually provides tracking
and tensioning controls. Work is applied to the contact wheel below
the centerline.
Back-up Pad
Usually a rubber or
composition type material to which an abrasive disc is attached. The
back-up pad supports the disc during the grinding operation and is
normally the same diameter or slightly smaller than the disc.
Balance (Dynamic)
A piece in static
balance is in dynamic balance if, upon rotating, there is no
vibration nor "whip" action resulting from unequal distribution of
its weight throughout its length.
Balance (Static)
A wheel or roll is in
static balance when, centered on a frictionless horizontal arbor, it
remains at rest in any position.
Bands (Abrasive)
Spirally-wound and
bonded to an inner liner, these cylindrically-shaped cloth
specialties are used on expanding rubber drums for sanding and
polishing hard-to-get-at corner, grooves, and contoured surfaces.
Barber Pole
A spiral pattern
produced on a workpiece during centerless or cylindrical grinding.
Normally caused by improper operating conditions.
Batch System
In rough lumber sanding,
several boards of equal or unequal widths of the same relative
thickness are accumulated side by side into a unit roughly equal to
the width of the abrasive belt in use. This "batch" is then fed into
the sander and all the boards are sanded
simultaneously.
Belt
Guard
A
protective device covering the abrasive belt, which is normally an
integral part of the grinding machine used to protect operators and
bystanders from personal injury.
Belt
Joint
The area
of an abrasive belt where the two ends are spliced together with an
adhesive. See Butt Joint and Lap Joint.
Belt
Joint Marks
A
pattern left on the workpiece at regular intervals, normally caused
by a belt joint specification that is not suitable for the
application.
Belt
Tension
The
force or strain put on a coated abrasive belt during use, normally
expressed in pounds per inch of belt width.
Bench
Stand
An
offhand grinding machine attached to a bench, usually has either one
or two wheels mounted on a horizontal spindle.
Bi Flex
(See
Double Flex).
Billy
Roll
A
pneumatic or hydraulic-actuated pressure roll used to apply pressure
forcing the work against a wide coated abrasive belt.
Blending
Using
abrasives to develop a consistent finish over an entire work-piece
as on a welded area.
Board
Foot
A unit
of measurement for lumber equal to the volume of a board 12" x 12" x
1", i.e., 144 cubic inches.
Body-in-the-White
An
automobile body in the intermediate assembly stage having a "raw"
metal surface at which time defects in the sheet metal surfaces are
removed and repaired, and exposed metal-to-metal joints are filled
with lead-solder.
Bond
See
Adhesive.
Bowed
Edge
A
condition affecting one or both edges of a coated abrasive belt or
roll. The belt or roll will arc or skew in one direction when laid
out on the floor, instead of following a straight line. Normally one
edge of the product is longer than the other.
Breaker
Rolls
Rolls
positioned before and after the grinding heads, that pull down the
side edges or center of the strip and open the surface of the steel
to enhance the ability of the coated abrasive to remove the surface
defects.
Brinnel
Number
A
hardness rating obtained from the Brinnel test; expressed in
kilograms per square millimeter.
Brinnel
Test
A test
to determine the hardness of a material in which a steel ball, one
centimeter in diameter, is pressed into the material with a standard
force (usually 3,000 kilograms). The spherical surface area of
indentation is measured and divided into the load with the results
expressed as the Brinnel number.
Buffing
The
smoothing and brightening of a surface utilizing an abrasive
compound pressed against it by soft wheel or belt.
Burning
the Work
A change
in the characteristics of the workpiece being ground. Normally
detected by a surface discoloration or distinct "burning" odor.
Burnishing
Using
coated abrasives to create a special effect on a workpiece (refining
the surface). Usually done to develop a smooth, lustrous surface
finish on metal, leather, etc.
Burrs
A thin,
ragged tin left on the edge of a piece of metal by a cutting tool
(including coated abrasives).
Bushing
A metal
or plastic insert used to alter the size of a center hole (primarily
in rolls or Flap Wheels) to accommodate a smaller mandrel or arbor.
Butt
Joint (Belt)
Two
pieces of coated abrasive "butted" together (with no overlap) to
form an endless belt. A very strong, thin, reinforcing patch is used
on the back of the butt joint to hold it
together.
Cabinet
Room (Furniture)
The
assembly area in a furniture plant where case goods are sanded
in-the-white, prior to staining.
Calendar
Roll
Steel,
rubber, or rolls of other composition, through which materials such
as paper, steel, etc., pass to thin them into sheets or to make them
smooth and glossy. A roll, usually rubber, that applies the adhesive
(bond) to a coated abrasive backing prior to the grain coating.
CAP Code
A
simplified system used to identify the various coated abrasive
products.
Cartridge Roll
See
Pencils.
Casting
Any
object (usually metal or plastic), which is formed by placing a
(castable) substance in a mold or form, and allowing it to solidify
through cooling.
Centerless Grinding
Abrasive
grinding and finishing the outside diameter of a round work-piece
not mounted on conventional centers (See Centerless Grinding
Application Section of manual).
Centers
Conical
steel pins of a grinding machine upon which the workpiece is
"centered" and rotated during grinding.
Chatter
An
undesirable, repetitive pattern created on the surface of a
workpiece, usually at regularly-spaced intervals, due to an
out-of-round or out-of-balance condition in the abrasive machine.
"Chicken"Treats
Small
interrupted indentations or raised areas, appearing as a pattern, on
a flat wood workpiece after sanding. Normally associated with wide
belt or oscillating drum sander applications.
Chips
Pieces
of material removed by an individual abrasive grain during the
abrasive grinding operation.
Chuck
A device
for holding a workpiece being ground.
Cladding
A
process by which two or more (usually dissimilar, e.g., stainless
steel and copper) metals are bonded together with heat and pressure,
to form a composite surface without the use of any adhesive.
Climb
Grinding
The
workpiece is presented to the abrasive belt in the same direction
the belt is running.
Closed
Coat
A coated
abrasive product completely covered by abrasive grain on the coat
side.
Coated
Abrasives
Products
formed by bonding abrasive grain with an adhesive to a flexible or
semi-rigid backing.
Coloring
(Color Buff)
Refers
to an operation that generates high lustre or ultra-fine finishes on
metal surfaces using buffing wheels and compounds.
Combination
A
strong-coated abrasive backing made by adhering print cloth to 110
pound paper.
Combination Sanding Head
A wide
belt grinding head that offers the option of using the contact roll
or platen either individually or in tandem.
Compensator
An
equipment option on wide belt sanders that reduces the feed speed of
the work transport system when excessively oversized work enters the
machine. This feature improves coated abrasive belt life and reduces
machine wear.
Concave
(Curl)
A coated
abrasive product with a curved (curled) configuration, which bulges
inward. The abrasive grain is always in the inside curve (grain side
concave).
Concentration
The
relative content of a component usually expressed as a % of total,
e.g., grain coverage, amount of inert filler I adhesive bonds, etc.
Contact
Wheel
The
wheel, usually rubber, metal, or felt, over which a coated abrasive
belt runs and against which work is applied. Aggressiveness varies
with density, angle, and depth of
serration (if any) and ratio of groove-width to land-width.
Contour
Sanding
The
sanding of irregular-shaped parts or compound moldings.
Conventional Grinding
The
workpiece is presented to the abrasive belt opposite the direction
the belt is running.
Conveyor
Belt
Usually
an endless belt configuration that positions, holds, moves, and
finally clears workpieces through the abrasive heads on a grinding
machine.
Conveyor
Machine
A coated
abrasive grinding machine on which the workpiece is moved by a belt
under the abrading head of the machine.
Convex
(Curl)
A coated
abrasive product with a curved (curled) configuration which bulges
outward. The abrasive grain is always on the outside curve (grain
side convex).
Coolant
The
liquid or solution used to cool the workpiece during grinding, and
to prevent it from rusting.
Creasing
(of a Belt)
Folding
of the coated abrasive belt on the contact roll or wheel because it
has become stretched in service, or is too flexible for the
operation. The term is also used to describe a light scoring of the
back of the belt so that it will "hinge" and fit into the complex
shape of a hand block.
Crocus
Essentially Iron Oxide in natural or synthetic form, Crocus coated
products are used mostly for cleaning corroded surfaces of polished
metals where a minimum of stock removal is desired.
Cross-Scratch
Refers
to a scratch created by sanding across or 90 degree to the direction
of the wood grain.
Crown
That
part of a sheet or contact roll face where the thickness or diameter
increases from edge to center.
Crushed
Joint (Belt)
A method
of reducing belt joint thickness slightly without top skiving the
joint. Used also to reduce abrasive grain aggressiveness at the belt
joint to prevent joint loading or marking of the workpiece.
Curl
Refers
to convex or concave curvature or twisting of a coated abrasive
product.
Cutt
Buff
A type
of cloth buffing wheel used in conjunction with an aggressive
buffing compound to remove minute surface irregularities in
preparation for final finishing.
Cutting
Rate
The
amount of material removed by a coated abrasive from the workpiece,
per unit of time.
Cylindrical Grinding
Grinding
the outside surface of a cylindrical part mounted on centers.
Deburring
Act of
removing burrs from metal.
DeLappe
Discs
Coated
abrasive discs which have radially-cut slits emanating from the
center hole or around the disc periphery. Used primarily in the
woodworking industry on felt spools for sanding contoured surfaces
and as a flutter sander for machine sanding grooves and routed
areas.
Density
The mass
of a given substance per unit volume usually expressed in
weight/pounds per cubic inch, etc.
Depth of
Cut
Refers
to the amount of stock removed during each pass of a sanding or
grinding operation. Usually expressed in thousandths of an inch,
e.g., depth of cut .125", etc.
Dimensions
The size
of a workpiece or coated abrasive product – normally expressed in
measurement of length, width, and often depth, e.g., 4’ x 8’ plywood
sheet, ¾" thick, or a 4" x 132" belt, or a 9-1/8" x 7/8" (center
hole) disc, etc.
Directional Arrow
Printed
on the back of coated abrasive belts, directional arrows point the
direction the belt should be run on the machine. Belts manufactured
with butt-type joints may be run in either direction and the arrow
will point in both directions. Flap Wheels also carry directional
arrows signifying propre direction of rotation.
Disc
A round,
flat coated abrasive product with or without a center clamping hole
that is affixed to a rotating plate or back-up pad for portable or
stationary grinding. Discs with other-than-round outer peripheries
are also manufactured for special applications.
Disc
Back-up Pad
A
support pad designed to back-up a coated abrasive disc during
grinding.
Disc
Grinder
A
machine on which abrasive discs are used for grinding.
Disc Nut
Used to
secure to back-up pad.
Discoloration
See
Burning the Work.
Dog Ear
A
protrusion, usually on one edge of a coated abrasive belt, at the
joint, caused by uneven belt cutting or improper joint alignment at
belt pressing.
DOM
Tubing
Tubing
that is expanded by forcing the tubing over a mandrel (Drawn Over
Mandrel).
Double
Flex
A
controlled breaking of the adhesive bond of a coated abrasive
product at two 45 degree angles to the length.
Down
Grade
The
diminishing of the value of lumber by creating defects during
processing. This commonly occurs during rotary knife planing when
tearouts, knot loss, and splitting occur.
Drawer
Sander
A
special machine for sanding the dovetails, front and rear, of wooden
drawers after assembly.
Drawing
Die Polisher
A unique
machine that employs narrow coated abrasive belts to polish drawing
dies. The die rotates horizontally on a revolving table. The coated
abrasive belt is operated in a vertical plane against the inside
diameter of the die. Abrasive belts range from ½" in width to as
narrow as 1/8".
Dressing
A term
used to describe the truing or restoring of a platen, contact wheel,
cutting tool, etc. to its original configuration.
Dressing
Tool (Dresser)
Any tool
or apparatus used for dressing something.
Drum
Cover
Refers
to the coated abrasive wrapped on the drums of a
multiple-drum-sanding machine.
Dry
Grinding
Refers
to any coated abrasive grinding operation that does not employ a
liquid coolant or grinding aid.
Dubbing
The
tapering of any of the edges of flat stock which has been processed
through a wide belt or drum sander. Most commonly occurs on the
leading or trailing edge of the work.
Ductile
Capable
of being readily pressed or drawn or otherwise formed into various
shapes without fracturing.
Dulling
This
wearing away of the cutting edges of abrasive grains through use. It
occurs to some degree during any abrasive operation and will finally
result in inefficient cutting or abrading, at which time the coated
abrasive should be discarded or shifted to lighter work, regardless
of its appearance.
Durometer
An
instrument used to measure hardness of rubber and other materials.
Consists of a small drill or blunt indenter point.
Durometer Hardness
The
hardness of a material as measured by a durometer.
Edge Cut
Grooving
or rounding of the edges of work caused by excessive stock removal
at the coated abrasive belt edge. Also called edge snipe.
Edge
Sander
A
machine used for edge sanding in a furniture plant.
Edge
Sanding
The
sanding of any furniture components requiring flatness and
squareness integrity, such as frame legs, end boards, etc.
Edge
Shed
A term
used to describe a condition in which the abrasive grain "shells"
off the edges of a coated abrasive product (usually a belt) during
use. Usually caused by too severe an application of the coated
abrasive product.
Emery
An
abrasive that is a natural composite of Corundum and Iron Oxide. The
grains are blocky, cut slowly, and tend to polish the material being
abraded.
End
Grain
That portion of a cut
piece of wood, which exposes the growth rings of a tree. An example
is the end of a 2 x 4.
F.E.P.A.
"Federation of European
Producers of Abrasives" –
Normally used to
describe a European grading system for abrasive grain to
differentiate it from the USA A.N.S.I. system. Products graded to
the F.E.P.A. system have the letter "P" prior to the grit
designation, e.g., P240, P36.
Feed (Cross)
On surface type sanding
operations (i.e., stroke sanding), the rate of horizontal feed of
the coated abrasive across the work.
Feed (Down)
On conveyor operations
or surface sanding, the distance at which the belt and contact wheel
are fed into the work.
Feed Lines
A pattern on the work
produced by grinding. The finer the finish, the finer and more
evident are these lines, due to surface reflectivity. Some types of
feed lines (barber pole) indicate incorrect grinding conditions.
Ferrous
Any metal alloy
containing iron, usually in major amount.
Fiber (Backing)
A very hard, strong,
coated abrasive backing material consisting of multiple plies of
impregnated paper. Used primarily for disc products.
Fibre Combination
A strong-coated abrasive
backing made by adhering print cloth to 10-mil thick fibre.
Fin
A thin projection on a
casting.
Fining Out
Generating super fine
finishes on a workpiece during the last stages of a coated abrasive
polishing operation. Either the last step in polishing, or as
preparation for subsequent buffing.
Finish
The surface quality of
appearance, such as that produced by sanding or polishing.
Finish Grinding
The final operation
which produces the desired finish on the workpiece.
Finishing Paper
Products manufactured on
"A" weight (40 pound) backings, normally in fine grits, usually used
to hand-sand for final finish on wood, metal, etc.
Finishing Room
Refers to the area in a
furniture plant where the primary sanding operations for finishing
furniture are performed, including wash coat sanding and sealer
sanding.
Fish Eye
A spot in a finished
coated surface, where the coating is sufficiently thinner than in
surrounding areas to cause a visible blemish. This defect is usually
caused by the presence on the surface, before coating, of a minute
trace of some chemical which prevents easy wetting of the surface by
the coating materials. Silicones are one of the most common classes
of chemicals oft his type, and, as a consequence, they are
rigorously excluded from high-quality coated abrasives.
Fixture
A device used to hold
and position the workpiece during the grinding and polishing
operations.
Flanges
Circular metal plates
used to support and drive contact wheels, BEAR-TEX Wheels, or Flap
Wheels.
Flap Wheel
Flat pieces of coated
abrasive sheets (flaps) arranged and fastened together on a core
like spokes of a wheel. The rotational slapping action of the flaps
does the abrading and polishing.
Flashing
A fin of excess metal
along the mold joint line of a casting, occurring between mating die
faces of a forging or expelled from a joint in resistance welding.
Flesh Buffing
Mechanical sanding of
leather, e.g., leathers that are finished by buffing the flesh side
(opposite the grain side) to produce a nap. The term "flesh buffing"
refers to the napping process, and is unrelated to the type of
animal skin used.
Flex
A controlled breaking of
the adhesive bond that holds the abrasive grain to the backing of a
coated abrasive product.
Fluting
Grinding the grooves of
a twist drill or tap.
Flutter Sanding
Sanding irregular,
intricate shapes or carvings which may be found on furniture frames,
legs, chair backs, etc. Normally done with eight winged DeLappe
Discs folded into a pinwheel configuration.
Foaming
A frothing of bubbles on
the surface of a liquid. Usually refers to "foam" in grinding aids,
etc., during the grinding process.
Folding
Normally refers to
creasing of a coated abrasive belt during use. (See Creasing).
Forging
Using compressive force
to shape metal by plastic deformation. Dies may be used. Also refers
to a piece of work made by forging.
Freehand Grinding
Grinding by holding the
work against the coated abrasive by hand; usually called Offhand
Grinding.
Friable
Referring to the
property of a substance capable of being easily rubbed, crumbled, or
pulverized into powder.
FTS
Abbreviation for Full
Top Skive (a type of belt lap joint configuration). All of the grain
is removed from the top lap of the joint for smooth running.
Gapped Joint
Refers to a belt joint
condition in which the two joint ends do not butt tightly together.
There is a space or "gap" at the point of contact of the belt ends.
Condition may lead to premature product failure.
Garnet
A coated abrasive grain,
red in color, made by crushing semi-precious garnet material. Coated
on both cloth and paper backings, Garnet is widely used in the
woodworking and furniture manufacturing industry.
Gate
The part of a casting
formed by the opening in the mold through which the metal is poured.
Generated Heat
Heat resulting from the
removal of metal or wood by a coated abrasive product.
Glazing
Formation of a layer of
the material being ground over the cutting edges of abrasive grains.
It can be avoided by proper selection of abrasive, contact wheels,
use of fluids or greases, or changing belt speeds.
Glue
A coated abrasive
adhesive produced by the hydrolysis of animal hides. It is
gelatinized by water and dries to form a strong adhesive layer and
may be used with or without a filler.
Glue Bond
Coated abrasive products
that use animal hide glue in both the maker and sizer adhesive
coats. The glue may be used alone or with an inert filler or
extender.
G.P.M.
Gallons per minute.
Grading
The process used to
separate abrasive grains into specific size groupings.
Grain
Abrasive particles
classified into predetermined sizes for use on coated abrasive
products.
Grain Fracture
Refers to the shape and
structure characteristics of abrasive grain used for coated abrasive
products, e.g., blocky, chisel shaped, strong wedges, etc.
Grain Size
The nominal size of the
abrasive particle expressed in grit number, e.g., grit 50.
Grain Spacing
The relative position of
the abrasive grain on the coated abrasive product, usually expressed
as open-coat or close-coat.
Graphite Coated Canvas
Canvas with a layer of
graphite adhered to it. Designed to reduce friction on a platen type
grinding machine, it is used between the platen and the back of the
belt.
Gravity Coat
A process by which the
abrasive grain is applied to the adhesive coating (of a coated
abrasive product) by gravity flow.
Grease Stick
Compounds of grease,
lubricants and binders sold in "stick" form, which are applied to
the coated abrasives during use to retard loading and improve metal
finishes.
Grinding
Removing material with a
coated abrasive product, usually referring to the use of coarser
grit sizes.
Grinding Action
Refers to the cutting
ability of, and the finish produced by, a coated abrasive.
Grinding Aid
The generic term
covering coolants and lubricants applied to coated abrasives to
improve cut, finish, and durability by reducing heat and loading.
May be water, various oils (in emulsion or straight), or greases in
stick form.
Grinding Burr
See Burrs.
Grinding Wheel
A cutting tool of
circular shape made of abrasive grains bonded together.
Grit
Designation of abrasive
grain size, reflecting the number of the smallest openings per
linear inch in the screen through which the grain will pass.
Groove
Refers to the slots in a
serrated contact wheel or roll adjacent to the lands. Land-to-groove
ratio has significant bearing on the aggressiveness of a contact
wheel.
Guards
Metal structures
covering exposed moving parts (fly-wheels, gear, etc.), as well as
the abrasive product, on a grinding and polishing machine, designed
to protect operators from personal injury.
Hand Block Sanding
Using a flat block or
formed block when sanding with belts or sheets, usually to finish
wood workpieces. Flat hand blocks are used to polish flat stock,
while formed blocks are sued to sand shaped moldings.
Heading
A technique used to
improve the finishing characteristic of abrasive belts. The process
impacts the voids between abrasive grains with a combination of oil
and generated swaff, to retard penetration of the abrasive into the
surface being polished, in order to produce uniform, burr-free
finishes.
Heat Check
Parallel surface cracks
forming a pattern on the surface of a metal as a result of thermal
fatigue.
Heat Crack
A crack or fissure in a
workpiece caused by excessive heat generated during the grinding
operation.
Heel Scouring
Shaving the heels of
shoes with a cutter to conform to the shoe shape leaves a ragged,
uneven edge. It is necessary to bring (scour) the edge to a smooth,
even surface which waxing and burnishing will keep bright and shiny.
Scouring is accomplished with silicon carbide coated abrasives.
Holddown
A device that holds the
outer portion of a metal sheet in place during deep drawing
operations, in order to keep it from becoming wrinkled. Used to
describe any fixture for holding a workpiece in position during a
grinding operation.
Hoods
A protective covering,
usually providing special ventilation, to carry away objectionable
fumes, dusts, etc., during the grinding process.
Idler
A machine part in a belt
system (may be adjustable) which provides belt tracking and, in some
installations, belt tensioning adjustments.
Idler Grooves
A configuration of slots
or grooves in an idler roll of an abrasive belt machine to prevent
coated abrasive belt hydroplaning during a wet grinding operation.
Inclusions
Usually mean cavities
denoting impurities in metal workpieces.
Indexing
A programmed progression
of grinding across a surface. To move the "feed" in steps.
In-Line System
A type of rough lumber
sanding system employing belts 14" to 30" wide and running with feed
speeds up to 700 FPM.
Intermediate Grinding
Those grinding
operations not considered either heavy stock removal or polishing.
Some stock removal present, but primary concern is to remove scratch
marks from previous coarse grits. Usually refers to operations using
grits 60 through 120.
Investment Casting
A casting method
designed to achieve high dimensional accuracy for small castings by
making a mold of refractory slurry, which sets at room temperature,
surrounding a wax pattern which is then melted out to leave a mold
without joints.
Jitterbug
A reciprocating or
oscillating sander that uses a coated abrasive sheet affixed to a
felt or rubber back-up for flat sanding of wood.
Joint
See Belt Joint.
Joint Angle
The angle of the belt
joint in relation to the edge of the belt. Expressed in degrees.
Joint Hinging
A condition describing a
belt joint that has taken an inward fix (gulled effect) at the point
of joining. On lighter weight products, the hinge will pull out
under tension. On heavier products the "hinge" may resist pulling
out and could weaken the belt joint and mark the workpiece.
Jumbo
A large roll of coated
abrasive product as it is wound after the manufacturing process.
Jumbos are then fabricated into finished shapes (sheets, discs,
belts, etc.) for industrial and consumer use.
Land
The surface between
successive grooves on a contact wheel or roll. The area of the
contact wheel that is in actual contact with the workpiece.
Land/Groove Ratio
The ratio of the widths
of the land to the grooves on a serrated contact wheel or roll,
e.g., land/grove ratio of 2 to 1= 1" land width, ½" groove width.
Lap Joint
Coated abrasive belt
joints formed by overlapping the two ends of the abrasive material
about 3/8" and bonding. The abrasive grain must always be removed
(skived) from the bottom lap prior to joining.
Lapping
A finishing process
typ8ically employing loose abrasive grain, now often including
similar types of operations with coated abrasives, e.g., crankshaft
and bearing lapping for engines.
Leather Split
Tick animal hides are
normally split or sliced to a specific thickness for given end uses.
The piece that contains the flesh side of the hide is referred to as
the "split" and is used in the manufacture of suede jackets, gloves,
etc.
Leveler
A series of opposed,
hardened steel rolls on a coil grinding machine that mechanically
reduces coil or sheet distortions prior to grinding and/or
polishing.
Line Contact
Point at which the
workpiece meets the coated abrasive belt on a contact wheel type
operation, as opposed to area contact of the workpiece on a platen
type application.
Linear Flex (L-Flex)
A controlled breaking of
the adhesive bond of a coated abrasive product in the direction of
the length (longitude).
Loading
Filling of the spaces
between abrasive grains on a coated abrasive product with grinding
swarf, resulting in a decrease in stock removal and rate of cut.
Loading can be reduced in many operations by using an open coat
product construction or a lubricant.
Load Meter
An optional feature on
wide belt sanding equipment. A meter that reads out the main motor
load during operation. Some meters are calibrated in percent of
rated horsepower.
Long Scratch
Scratch pattern (long
scratches) exhibited on a workpiece after stroke sanding or flat
platen type sanding vs. a short ‘scratch" from a contact wheel or
roll operation.
Lubricant
Liquid or solutions used
to lubricate the coated abrasive for cooling and to promote a more
efficient cutting action.
Machine Room
The area of a furniture
plant where the rough cut lumber is dimensioned, glued into panels,
and machined. The dimensioning portion of this operation is
frequently carried out on wide belt abrasive planers.
Magnetic Platen
A platen that is
magnetized to hold (secure) ferrous metal parts during the grinding
operation.
Maker (Machine)
A machine that
manufactures coated abrasive products by combining the backing,
adhesive, and abrasive grain.
Making
The process of producing
coated abrasive products.
Making Coat
The first adhesive coat
which adheres the abrasive grain to the backing of a coated abrasive
product, thereby ensuring proper anchoring and orientation of the
abrasive grain.
Malleable
Capable of undergoing
plastic deformation without rupture. A property characteristic of
metals that makes them easily "workable".
Mandrel
A metal rod or support
used to mount SPIRAPOINTS, Pencils, cross and square pads, disc
sets, or loose pieces of coated abrasives to be held in the chuck of
a grinder for grinding and polishing.
MTS Joint
Medium Top Skive –
Standard top lap joint skive depth for a TJ coated abrasive belt
joint, grits 40 through 80. Some of the grain is removed from the
joint top lap.
Matte Finish
Dull, as applied to the
appearance of a surface.
Maximum Operating Speed
Highest permissible
operating speed (RPM) marked on a coated abrasive disc back-up pad
or Flap Wheel.
Micro Finish
A measure of surface
finish. Usually expressed in RMS (Root Mean Square).
Micron Size
A unit of measure used
to compare abrasive grain size, e.g., 1 micron = .000039; grit 320 =
approximately 36 microns.
Mirror Finish
A shiny, highly
reflective finish on a workpiece. Distortion –free, without flaw.
Modular
A grinding machine
constructed in similar sections (modules), that can be added to or
taken away, depending on the particular application, e.g., adding or
subtracting head units from a centerless grinder.
Mohs Scale
An empirical scale
consisting of 10 minerals, with reference to which the hardness of
all other minerals is measured. It includes softest mineral
(designated 1 to hardest 10: talc, gypsum, calcite, fluorite,
opatile, orthoclase, quartz, topaz, corundum, and diamond.
Mold Block
A preshaped back-up
block that is positioned in back of an abrasive belt that will
conform to the molding being processed or finished. Blocks can
either be held by hand and guided over the straight line molding, or
held in a stationary fixture and the operator or sander pushes the
molded stock against it. In all cases, the coated abrasive belt is
held
between the sanding
block and the work.
Mold Sanding
Sanding and finishing of
wood moldings using a mold block and very flexible coated abrasive
belts.
MYLOK
A butt type belt joint
similar in construction to PLYWELD. This joint utilizes a very thin
plastic patch material designed to give "bump free" operation of the
belt when the joint is run over a steel platen or used with a very
hard contact wheel.
Nailboard
Describes a small, thin
wooden file-shaped board to which coated abrasive products are
affixed to each side; usually fine grit Flint on one side – fine
grit Garnet on the other. Used to file and trim fingernails.
Natural Abrasives
Used to differentiate
abrasives that occur in nature as opposed to electric furnace type
abrasives. Natural abrasives used for coated abrasives are Garnet,
Flint, Crocus and Emery.
Non-Ferrous
Any metal other than
iron ad its alloys.
NTS Joint
No Top Skive – A coated
abrasive belt lap joint with no skiving of the top lap, i.e. no
grain is removed from the top lap.
O.E.M.
Original Equipment
Manufacturer – Refers to manufacturers of equipment that utilizes
coated abrasive products.
Offhand Grinding
Applying the workpiece
manually to the moving coated abrasive, as when holding it freehand
against an abrasive belt.
Oiling Out
Term used by polishers
to describe the operation of using a fine grit abrasive, usually
with oil or a grease stick applied to the belt, to achieve the final
workpiece finish.
Open Coat
A coated abrasive
product in which the abrasive grain covers approximately 50% to 70%
of the coat side surface.
Operating Speed
The speed of a coated
abrasive product in use, expressed in either revolutions per minute
or surface feet per minute.
Orange Peel
An irregular ripple
pattern on a pickled or painted surface similar in appearance to the
pattern on the skin of an orange. It must be removed by adequate
sanding to obtain a perfect finish.
Oscillation
A slight, repetitive
lateral movement of a belt on its pulleys, designed to break up
parallel scratch patterns, produce fine finishes, and dislodge swarf
particles.
Oscillating Sander
A pad type sander with a
coated abrasive sheet fastened thereon, which uses a short,
high-speed oscillating stroke, producing fast stock removal.
Overrun (Lumber)
The amount of lumber
obtained from a given log above a target amount determined before
processing.
"P" Grade
See F.E.P.A.
Pad Sander
A small, handheld
machine using coated abrasive sheets fastened to the pad.
Parting Line
A line or seam on a cast
or molded part corresponding to the joint of mold parts.
Pencils
Sometimes called
"cartridge rolls", pencils consist of a continuous strip of aluminum
oxide cloth wound around a center hole designed to accept the
mandrel of a high-speed power tool.
Peripheral Speed
The speed at which any
point on the outside periphery of a rotating tool is traveling when
the tool or wheel is revolving. Expressed in surface feet per minute
(S.F.P.M.) and determined by multiplying the circumference in feet
by the wheel or disc revolutions per minute.
Pickling
Preferential removal of
oxide or mill scale from the surface of a metal by immersion usually
in an acidic or alkaline solution.
Pinch Rolls
A set or series of
opposed rolls (usually rubber), which apply pressure to the work
piece to maintain proper feed rate and workpiece alignment during
the abrasive grinding operations.
Pits
Small holes in the
surface of a metal, usually caused by corrosion or formed during
electroplating operations.
Plastometer
Instrument used to
determine the flow properties of a thermoplastic resin by forcing
molten resin through a specified die opening or orifice at a given
pressure and temperature.
Platen
A flat or shaped support
which backs up a coated abrasive belt in the area where the
workpiece is applied. Usually metal or wood, the platen may be
surfaced with resilient material and a lubricant such as graphite
covered canvas.
Platen Grinder
A coated abrasive
machine utilizing a platen. The platen provides an area contact to
the coated abrasive. Unit pressures are usually low.
Plunge Grinding
The grinding or
polishing of an entire surface in one thrust as opposed to several
passes. Direct infeed is used; there is no cross-feed. The abrasive
belt must be wider than the workpiece.
Pneumatic Drum Sanding
Contour sanding of chair
stock and related parts with coated abrasive sleeves mounted on
canvas-covered inflatable rubber drums.
Polishing
Act of smoothing off the
roughness or putting a high finish on metal by using a coated
abrasive polishing belt.
Polishing Jack
A machine that uses
setup wheels or buffs for polishing. Very easily converted to use
coated abrasive belts.
Polyester
A synthetic cloth
material used as a backing for coated abrasive products.
Portable Grinder
A coated abrasive
sanding machine that is used by hand (manually) and can be easily
transported, e.g., portable disc and belt sanders.
Pouncing Paper
A coated abrasive paper
used to "pounce" or finish felt hats. The pouncing process removes
hair fibres, producing a smooth, even nap on hat crowns and brims.
Precision Work
Work which is required
to be exact in measurements, finish, etc. Work that must be ground
with great care.
Pressure Assist
Using a pneumatic or
hydraulic fixture to present the workpiece to the belt. Incorporates
uniform and faster stock removal by maintaining constant pressure;
lessens operator fatigue; eliminates overgrinding and ensures part
uniformity.
Profile
Refers to the surface
configuration of a workpiece, namely. Detail of grinding surface,
finish, flatness, etc.
Profilometer
An instrument for
measuring the degree of surface smoothness in micro inches, "RMS".
PSA (Pressure-Sensitive
Adhesive)
An adhesive applied to
the backing of coated abrasive products which permits easy product
application and removal to and from a back-up pad.
PSI (Pounds Per Square
Inch)
A unit of pressure equal
to the pressure resulting from a force of one pound applied
uniformly over an area of one square inch.
Pump Drum
Inflatable drums made of
rubber covered with a canvas boot, used for contour sanding chair
stock and related parts. The abrasive cloth sleeve is mounted and
the drum is inflated to whatever density is required.
Pump Sleeve
Coated abrasive product
that is made for mounting on a pneumatic pump drum.
Q-Flex
A controlled breaking of
the adhesive bond of a coated abrasive product providing a uniform
flex over the entire abrasive surface in all directions. The
excellent conformability of Q-Flex makes it ideal for belt grinding
over the edges of contact rolls and similar operations.
Random Finish
A non-directional
scratch pattern generated on a workpiece during a coated abrasive
grinding operation.
Regulating Belt
Used in centerless
grinding, regulating belts are either a coated abrasive product or
made from leather or a rubber belting composition. They are run over
a steel platen, normally with a carbide insert to prevent wear, and
function the same as the regulating wheel.
Regulating Wheel
Used in centerless
grinding, regulating wheels function both as a frictional driving
and braking element, rotating the work at a constant and uniform
surface speed.
Resin
A synthetic adhesive
used as a bonding coat for coated abrasive products.
RMS (Root Mean Square)
A measure of surface
finish.
Rockwell Hardness
A measure of hardness of
a material as determined by the Rockwell hardness test.
Roll Grinding Machine
A machine for grinding
cylindrical rolls, used for rolling metal, paper, or rubber.
Rolls
A form of coated
abrasives (usually in 50 yd. Lengths) in widths from ½" to 52". Sold
in roll form to be converted by the customer.
Rough Grinding
The first grinding
operation for reducing stock rapidly without regard for the quality
of the finish.
Rough Lumber Sanding
Refers to the first
sanding operation on lumber, after the sawing operation.
RPM
Revolutions per minute.
Rubbing
The final phrase of
finishing in which the part surface is "rubbed " by machine or hand
to give the required lustre.
Sanding Room
Designates a department
in a furniture plant that is devoted primarily to machine sanding of
dimension stock prior to assembly.
Satin Finish
A smooth but not highly
reflective surface finish on metal.
Satining
A precision leveling of
the coated abrasive surface to ensure against scratching of soft
materials.
Scalloped Edge Belts
Belts with edges slit in
the pattern of a scallop. Used to overhand the edge of a contact
wheel to grind or polish a fillet in a workpiece.
Scleroscope
An instrument for
determining the relative hardness of material by a drop and rebound
method.
Scored Rolls
Coated abrasive roll
material with parallel slits evenly spaced in the length direction.
Used for making assemblies.
Scratching
Marks left on a ground
surface by dirty coolant contamination or improper coated abrasive
specification for the operation.
Sealer Coat
A coat of finishing
material (generally nitrocellulose in nature) designed to close the
pores on wood and promote adhesion of subsequent finishing
materials.
Sealer Sanding
Removing the roughness
or surface impurities from the sealer coat surface prior to the
finish lacquer coat.
Seaming Glass
Smoothing and easing of
the edges and corners of flat glass prior to tempering.
Sectional Belt
A coated abrasive belt
made of sections spliced together to produce belt widths greater
than the maximum product coating width. Contains two or more joints
per belt.
Serrated Contact Roll
Contact roll or wheel
with grooves milled into the face to increase the cutting action of
the coated abrasive belt and prolong belt life.
SFPM
Surface Feet Per Minute.
Shedding
Term used to denote the
loss of abrasive grain from a product during the grinding process.
Shelling
See Shedding.
Shoe
Technically referred to
as a platen or smoothing bar. A flat metal support located behind
the coated abrasive belt. Frequently faced with felt or vinyl foam
tape to provide resiliency.
Shore Durometer
A method of rating the
hardness of rubber, plastic, or other material.
Short Scratch
Generated by a contact
roll application as opposed to a stroke sander or platen type
operation.
Silicon Carbide
An abrasive made from
coke and silica sand (SIC).
Single Flex
A controlled breaking of
the adhesive bond of a coated abrasive product at a 90 degree angle
to the length. The coated abrasive product is stiff in one
direction, flexible in the other.
Size Coat
Second adhesive coat
applied to a coated abrasive product. The "size" coat unites with
the maker coat and insures the final anchoring of the grain and
propre total adhesive level to the finished product.
Skive
Refers to the grain
removal and taper operation performed on both laps (ends) of coated
abrasive belt prior to joining the two laps necessary in order to
achieve adequate joint adhesion and desired joint thickness.
Slack of Belt Sander
A machine configuration
in which the workpiece is presented to the coated abrasive belt in
the area between the two pulleys. Work applied to unsupported area
of belt.
Slag Grinding
A wide belt conveyor
type grinding operation that replaces portable tool grinding methods
for removing slag, scale, and torch splatter from the surface and
edges of flame cut and/or plasma cut steel parts.
Slivers
Thin, elongated
fragments of metal that have been rolled into the surface of the
parent metal and are attached by only one end.
Slotted Discs
Coated abrasive discs
containing numerous radial slots cut from the outside periphery.
Slurry Coat
Refers to a coating
method in which the abrasive grain and adhesive are mixed together
and metered onto the backing in one continuous coating.
Smoothing Bar
A platen type device
backing up the coated abrasive belt at the point of contact with the
workpiece. Usually covered with graphite canvas to reduce frictional
heat. Used on wide belt machines in woodworking, particleboard and
plywood sanding to promote better finishes.
Snagging
Grinding the gates,
fins, and sprues from castings.
Soluble Oil
An emulsifying oil
which, when mixed with water, forms an emulsion. Soluble oil
mixtures are sometimes used to achieve better finishing than can be
produced by dry grinding or by water alone. The water frees the belt
of particles and the oil prevents rust from forming on the exposed
machine part.
Specialties
Coated abrasive forms
other than sheets, rolls, belts and discs, e.g., assemblies, Flap
Wheels, cones, etc.
Spindle
See Arbor.
Spool Sanding
Sanding convex or
concave profiles on curves such as mirror frames, headboards, and
other compound shapes. See Product Application and Selection Section
for Spool Sanding.
Spray Mist
A method of supplying
coolant to the workpiece or coated abrasive belt during metal
finishing operations, as opposed to a full flood coat.
Stamping Burr
A burr caused by
stamping dies.
Steady Rest
A support for workpieces
being ground on a cylindrical grinding machine.
Straight Line Sanding
Refers to a simple
reciprocating type hand sander as opposed to a sander employing
orbital motion.
Strapping
Refers to a method of
applying a workpiece to the unsupported portion of a belt, to
conform to irregular shapes. Also, refers to a method of hand
application of coated abrasives, i.e., using a strip of coated
abrasives shoeshine fashion.
Stress Relief
See Back Pass.
Stretch
Elongation of a coated
abrasive product during use (normally refers to stretch of the
coated abrasive belt.)
Strip Scouring
The process of removing
stains, oils, films, oxide skins, and any other surface defects that
would disqualify coils or strip steel from being used as decorative
trim.
Stripped Grain
See Shedding.
Stroke Sander
A machine that makes
sanding contact by "stroking" the back of a moving coated abrasive
belt with a back-up block or pad. Essentially, these machines
consist of two or more pulleys over which the coated abrasive belt
travels, a table which supports the workpiece, and means for
applying pressure and movement along the belt.
Strong Shaped Grain
Abrasive grain more
wedge shaped and/or blocky in shape as opposed to a slivery or
weakened shape (needle) grains.
Sueding
Refers to the process of
producing a velvet finish on the flesh side of leather, cloth, etc.
Surface Finish
The quality of a
workpiece finish expressed in RMS or other quantifiable or
subjective measure.
Surface Grinding Machine
A machine for grinding
or finishing plane (flat) surfaces.
Swarf
The mixture of workpiece
residue and abrasive particles with grinding aid (water, oil)
created by abrading action.
Swingframe Grinder
A grinding machine
suspended by a chain at the balance point so that it may be turned
and swung in any direction, for the grinding of billets, large
castings, or other heavy work.
Swirl Marks
Grinding marks or
scratch patters left by rotational type tools.
Synthetic
Refers to a coated
abrasive cloth backing other than cotton, e.g., Polyester, Rayon,
etc.
Table
That part of the
grinding machine which directly or indirectly supports the work
being ground.
Temper
The heat treatment of a