Glossary
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 material to develop required qualities.
Tensile Strength
The maximum stress a material, subjected to a stretching load, can withstand without tearing. Usually expressed in pounds per square inch.
Tension
The condition of a coated abrasive belt that is stretched between two points on a grinding machine (under tension); the force exerted by the coated abrasive belt on a support.
Tensioning Cylinder
A method or apparatus for supplying continuous tension to a coated abrasive belt during use.
Terminal Equipment
Refers to equipment or apparatus other than the grinding machine itself, e.g., unwind stands and windups for coil grinding, fixtures for positioning workpieces or removing them after sanding, etc.
Thermo Setting (Resin)
Characterized by hardening when heated above a certain temperature, to a state which remains hard even if subjected to additional heating.
Thermal Tempering
Heat treating of hardened steels to temperatures below the transformation temperature range, usually to improve toughness.
Thermoplastic (Resin)
A material with a linear micro molecular structure that will repeatedly soften when heated and harden when cooled.
TJ Joint
Thin Joint – Special coated abrasive belt lap joint construction for use in applications where a smooth-running product with minimum joint thickness is a necessity.
Tolerances
The permissible variations in the dimensions of machine parts or the permissible deviation from a specified value in a manufacturing specification or procedure.
Tooth
One of the regular projections on the edge or face of a gear wheel. The coarseness or abrasive quality or a surface, e.g., roughing a surface for better adhesion of veneers, etc.
Torn Edge Belt
A coated abrasive belt fabricated with one belt edge torn lengthwise and joined along a warp thread to ensure straight tearing of subsequent narrower belts when they are ripped. Using the torn edge of the original belt as a starting point, narrower width belts can be ripped in succession across, until the original belt is used up.
Tracking
The act of adjusting the idler pulley in a coated abrasive belt system so that the belt is properly aligned on the contact wheel.
Traverse Speed
Speed at which either the grinding head or the workpiece moves laterally during grinding or polishing.
Triple Flex
A combination of Single Flex and Double Flex. Specified on certain products for sanding irregular contours where maximum product conformability is a requirement.
Truing
The procedure used to restore a flat surface to a contact wheel or platen.
Tumbling
An operation for deburring, breaking sharp edges, finishing, or polishing, in which abrasive, water, and the work parts are “tumbled” in rotating or vibrating barrel.
UNIFLOW Belt
Sometimes called “Sleeves”, this abrasive specialty is formed with a belt type joint. Used on soft drums at relatively low speeds for removing tool marks and developing special finishes. Available in widths up through 9″ and lengths up through 11″.
Up Coat
Refers to an electrostatic method (upward propulsion) of coating abrasive grain on a coated abrasive product.
Vickers
A system for measuring metal hardness using a triangular diamond which is pressed into the metal surface under a fixed preload.
Vonnegut Assembly
See Assemblies.
Vonnegut Wheel
Brush-backed wheel containing a loading of coated abrasive strips, used to sand contoured workpieces.
Wash Coat
A very light coat of finishing material primarily adding depth to the color of furniture after staining. The solution is sprayed on and requires light scuffing.
Waterproof Abrasive
A coated abrasive which will withstand grinding with water or water soluble oil as a grinding aid.
Weak Shaped Grain
Needle shaped, very friable, easily fractured abrasive grain, as opposed to “strong shaped grain”.
Web
Refers to a flat-coated abrasive product, usually in full width form, as it passes through the manufacturing process.
Wet Grinding
A term used to describe full flood oil grinding and full flood water soluble methods. All methods other than absolutely dry are included.
Whiting
Finely ground clay and/or limestone used to absorb oil from stainless steel after polishing.
Wild Scratch
A heavier-than-normal scratch in a workpiece finish. Usually intermittent or random, caused by a coarse particle, contamination of swarf, etc.
Work Rest Blade
Supports the material being ground during a centerless grinding operation.
Work Rest Blade Angle
Angle at which the work rest blade meets the workpiece – 20 degrees to 30 degrees angle is customary.
Work Rest Blade Holder
Holds work rest blade in position during centerless grinding.
Work Speed
In cylindrical and centerless grinding, the rate at which the work revolves, measured in either RPM or SFPM. In surface, conveyor, or feed type grinding, the rate of work presentation to the coated abrasive, measured in FPM (feet per minute).
Yield
Refers to the total amount of processed lumber realized from a Log.
Zirconium Alumina
A term used to describe coated abrasives which utilize a special synthetic grain that gives the most effective performance in a variety of applications.