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Abrasives Glossary

The general terms used in abrasives industry

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, Zirconia Alumina and ceramics. One of the three basic components of a coated abrasive product (backing, bond, 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

Sanding of glued-up or lumber banded man-made board panels prior to intermediate sanding or the application of overlays.

Aluminum Oxide

An abrasive made by fusing the mineral bauxite (Al203).

Anneal

Treatment of metals and other materials with heat and then cooling to soften and make 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.

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. Also measure of surface roughness. See RMS.

Area of Contact

The area of the surface of a coated abrasive product in contact with the work being ground.

Assemblies

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 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 and idler. Usually used on belt machines 12" and wider.

Backing

A flexible or semi-rigid material to which abrasive grain is bonded by an adhesive. Paper, cloth, fiber 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 or polishing operations on the finish side.

Backstand

One of the most popular and common industrial abrasive belt machines for offhand or other grinding and polishing. Basically consists of a contact wheel and one or more idlers for tensioning and tracking the belt.

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 wheel or roll in balance at operating RPM.

Balance (Static)

A wheel or roll is in static balance when, centered on a frictionless horizontal arbor, it remains at rest in any position.

Barber Pole

A spiral pattern produced on a workpiece during centerless or cylindrical grinding. Normally caused by improper operating conditions.

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 Splice

The area of an abrasive belt where the two ends are joined together with an adhesive to make an endless belt.

Belt Splice Marks

A pattern left on the workpiece at regular intervals, normally caused by a belt splice specification that is not suitable for the application.

Belt Tension

The force or strain put on a coated abrasive belt by the idler during use, normally expressed in pounds per inch of belt width.

Bench Backstand

An offhand grinding machine attached to a bench. Usually has either one or two wheels mounted on a horizontal spindle with idlers to tension and track the belts.

Billy Roll

A pneumatic or hydraulicactuated pressure roll used to force the work against a wide coated abrasive belt.

Blending

Using abrasives to develop a consistent finish over an entire workpiece, 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.

Bond

The substance used to adhere the grain to the backing on a coated abrasive product.

Breaker Rolls

Rolls positioned before and after the grinding heads to bend strip or coil stock over the billy roll to insure straight cylindrical contact at the point of grinding.

Brinnel Number

A hardness rating obtained from the Brinnel test; expressed in kilograms per square millimeter.

Buffing

The smoothing and brightening of a surface utilizing an abrasive compound applied to a fabric type 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

Refining a surface using fine grit coated abrasives to create a special effect with minimum stock removal.

Burrs

A thin, ragged fin, 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 Splice (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 splice 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 in tandem through which materials pass to produce uniform thickness and/or a smooth, glossy surface. A roll, usually rubber, that applies the bond to a coated abrasive backing prior to the grain coating.

C.A.M.I.

"Coated Abrasives Manufacturer's Institute". A trade association composed of U.S. coated abrasives manufacturers.

Cartridge Roll

A strip of coated abrasive wound in multiple wraps around a center hole and glued. Mounted on a mandrel used on a high speed portable tool for intricate polishing.

Casting

A shaped part produced by placing molten metal or a castable substance in a form or mold and allowing it to solidify by cooling.

Centerless Grinding

Abrasive grinding and finishing the outside diameter of a round workpiece not mounted on conventional centers (see Centerless Grinding Application section of manual).

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.

Chips

Pieces of material removed by an individual abrasive grain during the abrasive grinding operation.

Climb Grinding

The workpiece moves in the same direction that 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 luster or ultrafine finishes on metal surfaces using buffing wheels and compounds.

Concave (Curl)

A coated abrasive product with a curved (curled) configuration in which the abrasive grain is in the inside curve (grain side concave).

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 (Mold)

The sanding of irregular shaped parts or compound moldings.

Conventional Grinding

The workpiece moves in the opposite direction from which the belt is running.

Conveyor Belt

Usually an endless Pelt 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 conveyor belt under the abrading head of the machine.

Convex (Curl)

A coated abrasive product with a curved (curled) configuration in which the abrasive grain is on the outside curve (grain side convex).

Coolant

A liquid grinding aid to improve abrasive performance.

Creasing (of a Belt)

Folding of the belt in use; typically, the crease is not parallel to the belt edge. Most often caused by machine wear or misalignment but can be caused by uneven side to side belt length.

Crocus

Essentially, iron oxide in natural or synthetic form, crocus coated products are used mostly for cleaning or finish polishing of metal surfaces where a minimum of stock removal is desired.

Crown

That part of a sheet or idler roll face where the thickness or diameter increases from edge to center. Crowned idlers are used for tracking narrow belts.

Curl

Refers to convex or concave curvature or twisting of a coated abrasive product.

Cut Buff

A type of cloth buffing wheel used in conjunction with an aggressive buffing compound to remove or refine scratch pattern produced by polishing in preparation for color buffing or plating.

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.

Deadhead

See Noseblock

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.

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 splices may be run in either direction and the arrow will point in both directions. Flap wheels also carry directional arrows signifying proper 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 backup 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 backup coated abrasive disc during grinding.

Drawer Sander

A special machine for sanding the dovetails, front and rear, of wooden drawers after assembly.

Dressing

Restoring the working face of a contact wheel or platen to its original configuration.

Dry Grinding

Refers to any coated abrasive grinding operation that does not employ a coolant or lubricant in the grinding process.

Dubbing

Rounding or tapering the edges of workpieces. May or may not be intentional or desirable.

Dulling

The 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 elastomeric materials.

Durometer Hardness

The hardness of a material as measured by a durometer

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.

Electrocoat

Method of coating grain to backing wherein the abrasive grain is electrostatically oriented to produce maximum sharpness and even spacing between adjacent grains.

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 may have the letter "P" prior to the grit designation, e.g., P240, P36.

Feed

Movement direction of the work in relation to the abrasive. May be thru-feed (longitudinal), down feed or in feed (depth of cut) or cross feed (lateral).

Feed Lines

Undesirable pattern on the work produced by grinding. Most commonly found as a spiral pattern on centerless, cylindrical and roll grinding. Usually caused by incorrect grinding procedure or alignment.

Ferrous

Any metal alloy containing iron, usually in major amount.

Fibre (Backing)

A very hard, strong, coated abrasive backing material consisting of multiple plies of impregnated paper. Used primarily for disc products.

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 or ap­pearance, such as that produced by sanding or polishing.

Finish Grinding

The final abrasive operation which produces the desired finish on the workpiece.

Finishing Room

Products manufactured on "A" weight (40 pound) backings, normally in fine grits, usually used to hand-sand for final finish on wood, metal, etc.

Fixture

A device used to hold and position the workpiece during grinding and polishing operations.

Flanges

Circular metal plates used to support and drive some contact 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.

Flex

A controlled breaking of the bond that holds the abrasive grain to the backing of a coated abrasive product.

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. Reduces performance of the abrasive.

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.

Forty-five (45) Flex

A controlled breaking of the adhesive bond of a coated abrasive product at 45° right and left hand angles to the length.

Friable

Referring to the property of a substance capable of being easily crumbled, or pulverized into powder.

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 wood-working and furniture manufacturing industry.

Gate

The part of a casting formed by the opening in the mold through which the metal is poured. Removed by grinding the gate flush with the casting.

Glazing

Formation of a layer of the material being ground over the cutting edges of abrasive grains. It can be avoided or minimized by proper selection of abrasive, contact wheels, use of fluids or greases, or changing belt speeds.

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.

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 Size

The nominal size of the abrasive particle expressed in grit number, e.g., 50 grit.

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 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.

Grit

Designation of abrasive grain size, reflecting the number of the smallest openings per linear inch in the screen through which the gram 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 used to sand shaped moldings.

Hold down Rolls

Pressure rolls used on conveyor belt machines to force the work firmly against the conveyor and prevent the work from slipping or skidding during grinding.

Idler

A non-powered wheel or pulley in an abrasive belt system. Usually provides belt tension and adjustment for tracking.

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.

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 or Sanding

One or more operations and grit sizes to refine the roughing marks prior to final finishing.

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 backup for flat sanding and finishing.

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 grooves on a serrated contact wheel or roll. The area of a serrated contact wheel that supports the belt at the point of contact with the work.

Land/Groove Ratio

The ratio of the widths of the land to the grooves on a serrated contact wheel or roll, e.g., land/groove ratio of 2 to 1=1" land width, 1/2" 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.

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.

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 electrical meter that shows the main motor load during operation. A common option found on mechanized or automated abrasive belt operations. Some are calibrated in percent of rated motor horsepower. Others show amperes (amps) being used.

Lubricant

A liquid or solid (grease stick) substance used on coated abrasives to reduce heat generated in the work and improve abrasive performance.

Machine Room

The area of 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.

Make 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 cartridge rolls, 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.

Maximum Operating Speed

Highest permissible operating speed (RPM) marked on a coated abrasive disc backup pad, flap wheel, or contact wheel.

Micro Finish

A measure of surface finish. Usually expressed in RMS (Root Mean Square).

Mirror Finish

A shiny, highly reflective fiish on a workpiece. Distortion free, without flaw.

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 to 1) to hardest (10); talc, gypsum, calcite, fluorite, opatite, 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 allowing the operator or sander to push the molded stock against it. In all cases, the coated abrasive belt moves 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.

Narrow Belts

Coated abrasive products made in belt form up to and including 12" in width.

Natural Abrasives

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, nickel, cobalt and their alloys.

NTS Splice

No Top Skive - A coated abrasive belt lap splice with no skiving of the top lap, i.e., no grain is removed from the top lap.

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, usually expressed in either revolutions per minute or surface feet per minute.

Orange Peel

A pattern or condition on some metal and painted surfaces similar in appearance to the pattern on the skin of an orange. It must be removed by adequate sanding or polishing to produce 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 with a straight line finish.

"P" Grade

See F.E.PA.

Parting Line

A line or seam on a cast or molded part corresponding to the joint of mold parts.

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 multi-plying the circumference in feet by the revolutions per minute (RPM) of the disc or wheel.

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 operation.

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 a surface where the direction of movement between the work and abrasive is infeed only. There is no cross feed.

Pneumatic Drum Sanding

Contour sanding of chair stock and related parts with coated abrasive sleeves mounted on canvas-covered inflatable rubber drums.

Polishing

Smoothing or refining a rougher finish or surface or imparting a fine finish on metals by the use of coated abrasives.

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 handled and manipulated by the operator.

Precision Work

Work which is required to be exact in measurements, finish, etc. Work that must be ground with great care.

Pressure Assist.

Use of a mechanical, pneumatic or hydraulic device to apply force to the workpiece in its contact with the abrasive belt.

Profile

Refers to the surface configuration of a workpiece, namely, details 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 backup pad.

PSl (Pounds Per Square Inch)

A unit of measure 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.

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 a 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. The regulating wheel or belt is usually tilted at an angle to the vertical. This angle and the SFPM of the wheel or belt determines the thru-feed rate of the work.

Resin

A synthetic adhesive used as a bonding agent or coat for coated abrasive products.

Resin Bond

See Resin.

RMS (Root Mean Square)

A method of averaging which emphasizes the large values in the data averaged. Often used for scratch depth as 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 which are used for rolling metal, paper, or rubber.

Rolls

A form of coated abrasives (usually in 50 yd. lengths) in widths from 1/2" to 52". Sold in roil 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 Planing

Refers to the first sanding operation on lumber after the sawing operation. A replacement for knife planing.

RPM

Revolutions per minute.

Rubbing

The final phase of finishing in which the part surface is "rubbed" by machine or hand using fine grit coated abrasives followed by a rubbing compound to produce the desired finish.

Sanding Room

Designates a department in a furniture plant that is devoted primarily to machine sanding of white wood dimensioning stock prior to assembly.

Satin Finish

A smooth but not highly reflective surface finish on metal.

Sealer Coat

A thin coat of finishing material designed to seal the pores and surface of wood to resist penetration and promote adhesion of the final finish coatings.

Sealer Sanding

Removing the roughness to level the surface and promote adhesion of the finish coats.

Seaming Glass

Smoothing and easing of the edges and corners of flat glass; beveling.

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 splices per belt.

Serrated Contact Roll

Contact roll or wheel with grooves spirally cut 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 by means other than attritive wear.

Shoe

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 and produce improved finish.

Shore Durometer

A method of rating the hardness of rubber, plastic, or other elastomeric material.

Silicon Carbide

A manufactured abrasive made from coke and silica sand (SiC).

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 proper 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 adhesion and desired splice 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.

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, particle-board and plywood sanding to promote better finishes.

Snagging

Grinding the gates, fins, and sprues from castings.

Soluble Oil

An emulsified oil that forms an emulsion when mixed with water. Typically used as a grinding aid to increase belt life. Opaque, usually milky in color.

Spool Sanding

Sanding convex or concave profiles on curves such as mirror frames, headboards, and other compound shapes using slotted discs (see DeLappe discs).

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.

Stroke Sander

A machine that makes sanding contact by "stroking" the back of a moving coated abrasive belt with a backup block or pad in the slack of belt area.

Surface Finish

The quality of a workpiece finish expressed in RMS or other quantifiable or subjective measure.

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 too large or heavy to take to the machine.

Swirl Marks

Circular grinding marks or scratch pattern left by rota­tional type tools such as discs.

Synthetic

Refers to a coated abrasive cloth backing other than cot­ton, e.g., polyester, rayon, etc.

Temper

The heat treatment of a material to develop required qualities.

Tensile Strength

The maximum stress a material can withstand without breaking when subjected to a stretching load. Expressed as pounds per inch for most coated abrasive backings and pounds per square inch for most other materials.

Tension

See Belt Tension.

Tensioning Cylinder

A method or apparatus, usually pneumatic, for supplying continuous tension to a coated abrasive belt during use.

Thermo Setting (Resin)

Characterized by hardening when heated above a certain temperature, to a state which remains hard even if subjected to additional heating.

Thermoplastic

A material that will repeatedly soften when heated and harden when cooled.

Tolerance

The permissible variations in the dimensions of machine parts or the permissible deviation from a specified value in a manufacturing specification or procedure.

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.

Truing

1. The procedure used to restore a flat surface to a worn contact wheel or platen.
2. Dressing a contact roll or wheel to make its surface run concentric with the axis.

Vonnegut Loading

See Assemblies.

Vonnegut Wheel

Brush-backed wheel containing a loading of coated abrasive strips used to sand or finish 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.

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.

Wide Belts

Coated abrasive products made in belt form over 12" wide (belts over 52" wide must frequently be supplied with multiple splices called "sectional belts").

Wild Scratch

A deeper 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° to 30° angle is customary.

Work Rest Blade Holder

Holds work rest blade in position during centerless grinding.

Work Speed

The rate at which the work moves when in contact with the abrasive belt. Usually expressed in FPM (feet per minute).

Zirconia Alumina

A manufactured abrasive grain that is effective on a variety of materials and applications.

TH Vina Company Limited

Office: 8F, Sannam Building, 78 Duy Tan Street, Dich Vong Hau Ward, Cau Giay District, Hanoi, Vietnam
Factory: Dai Dong Hamlet, Dai Mach Commune, Dong Anh District, Hanoi, Vietnam
Telephone: +84 24 3993 7659
Hotline: +84 339 310 624

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