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Encyclopedia > Abrasive

An abrasive is a material, often a mineral, that is used to shape or finish (see metal polishing and wood finishing) a workpiece through rubbing which leads to part of the workpiece being worn away. While finishing a material often means polishing it to gain a smooth, reflective surface it can also involve roughening as in satin, matte or beaded finishes. A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure and specific physical properties. ... Metal polishing, also termed Buffing, is the process of smoothing metals and alloys and polishing to a bright, smooth mirror-like finish. ... Wood finishing refers to the process of embellishing and/or protecting the surface. ...


Abrasives are extremely commonplace and are used very extensively in a wide variety of industrial, domestic, and technological applications. This gives rise to a large variation in the physical and chemical composition of abrasives as well as the shape of the abrasive. Common uses for abrasives include grinding, polishing, buffing, honing, cutting, drilling, sharpening and sanding. (For simplicity, "mineral" in this article will be used loosely to refer to both minerals and mineral-like substances whether man-made or not.) The word grinding can mean many things: Grinding is a manufacturing process that uses friction with a rough surface to wear away or smooth the surface of a work piece - see grinding machine. ... Metal polishing, also termed Buffing, is the process of smoothing metals and alloys and polishing to a bright, smooth mirror-like finish. ... Honing could refer to Improving surface finish & geometry using a Hone the practice of sharpening Honing, Norfolk Category: ... For other uses, including articles on self-injury, see Cutting (disambiguation). ... An electric drill A drill is a tool with a rotary drill bit used to bore holes through material. ... A hand-cranked knife sharpener in Chennai. ... sheets of sandpaper Sandpaper is a form of paper where an abrasive material has been fixed to its surface; it is part of the coated abrasives family of abrasive products. ...


Files act by abrasion but are not classed as abrasives as they are a shaped bar of metal. However, diamond files are a form of coated abrasive (as they are metal rods coated with diamond powder). Detail of a double-cut flat file A file (or hand-file) is a hand tool used to shape material by cutting. ...


Abrasives give rise to a form of wound called an abrasion or even an excoriation. Abrasions may arise following strong contract with surfaces made things such as concrete, stone, wood, carpet and roads, though these surfaces are not intended for use as abrasives. Abrasion on the palm of a right hand, shortly after falling Abrasions on elbow and lower arm, still healing. ... An excoriation is an erosion or destruction of the skin by mechanical means, which appears in the form of a scratch or abrasion of the skin. ... Concrete being poured, raked and vibrated into place in residential construction in Toronto, Ontario, Canada. ... Trunks A tree trunk as found at the Veluwe, The Netherlands Wood is a solid material derived from woody plants, notably trees but also shrubs. ... A carpet is any loom-woven, felted textile or grass floor covering. ... Mountain road with hairpin turns in the French Alps For other uses, see Road (disambiguation). ...

Contents

Mechanics of abrasion

Abrasives generally rely upon a difference in hardness between the abrasive and the material being worked upon, the abrasive being the harder of the two substances. However, this is not necessary as any two solid materials that repeatedly rub against each other will tend to wear each other away (such as softer shoe soles wearing away wooden or stone steps over decades or centuries or glaciers abrading stone valleys). Glacial and Glaciation redirect here. ...


Typically, materials used as abrasives are either hard minerals (rated at 7 or above on Mohs scale of mineral hardness) or are synthetic stones, some of which may be chemically and physically identical to naturally occurring minerals but which cannot be called minerals as they did not arise naturally. (While useful for comparative purposes, the Mohs scale is of limited value to materials engineers as it is an arbitrary, ordinal, irregular scale.) Diamond, a common abrasive, for instance occurs both naturally and is industrially produced , as is corundum which occurs naturally but which is nowadays more commonly manufactured from bauxite.[1] However, even softer minerals like calcium carbonate are used as abrasives, such as "polishing agents" in toothpaste. Minerals are natural compounds formed through geological processes. ... This article or section does not cite any references or sources. ... This article is about the gemstone. ... Corundum (from Tamil kurundam) is a crystalline form of aluminium oxide and one of the rock-forming minerals. ... Bauxite with penny Bauxite with core of unweathered rock Bauxite is an aluminium ore. ... Calcium carbonate is a chemical compound, with chemical formula CaCO3. ...

Grit size ranging from 2 mm (the large grain) (about F 10 using FEPA standards) to about 40 micrometres (about F 240 or P 360).
Grit size ranging from 2 mm (the large grain) (about F 10 using FEPA standards) to about 40 micrometres (about F 240 or P 360).

These minerals are either crushed or are already of a sufficiently small size (anywhere from macroscopic grains as large as about 2 mm to microscopic grains about 0.001 mm in diameter) to permit their use as an abrasive. These grains, commonly called grit, have rough edges, often terminating in points which will decrease the surface area in contact and increase the localised contact pressure. The abrasive and the material to be worked are brought into contact while in relative motion to each other. Force applied through the grains causes fragments of the worked material to break away while simultaneously smoothing the abrasive grain and/or causing the grain to work loose from the rest of the abrasive. Image File history File linksMetadata Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 391 KB, MIME type: image/jpeg) Sand from Qafsah, Tunesia (small grains) and Worthing, England (large grain). ... Image File history File linksMetadata Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 391 KB, MIME type: image/jpeg) Sand from Qafsah, Tunesia (small grains) and Worthing, England (large grain). ... Look up grit, GRIT, grits, GRITS in Wiktionary, the free dictionary. ... The use of water pressure - the Captain Cook Memorial Jet in Lake Burley Griffin in Canberra, Australia. ...


Some factors which will affect how quickly a substance is abraded include:

  • Difference in hardness between the two substances: a much harder abrasive will cut faster and deeper
  • Grain size (grit size): larger grains will cut faster as they also cut deeper
  • Adhesion between grains, between grains and backing, between grains and matrix: determines how quickly grains are lost from the abrasive and how soon fresh grains, if present, are exposed
  • Contact force: more force will cause faster abrasion
  • Loading: worn abrasive and cast off work material tends to fill spaces between abrasive grains so reducing cutting efficiency while increasing friction
  • Use of lubricant/coolant/metalworking fluid: Can carry away swarf (preventing loading), transport heat (which may affect the physical properties of the workpiece or the abrasive), decrease friction (with the substrate or matrix), suspend worn work material and abrasives allowing for a finer finish, conduct stress to the workpiece.

Various examples of swarf, including a block of compressed swarf Swarf (or turnings) is shavings and chippings of metal -- the debris or waste resulting from metalworking operations. ...

Abrasive minerals

Abrasives may be classified as either natural or synthetic. When discussing sharpening stones, natural stones have long been considered superior but advances in material technology are seeing this distinction become less distinct. Many synthetic abrasives are effectively identical to a natural mineral, differing only in that the synthetic mineral has been manufactured rather than been mined. Impurities in the natural mineral may make it less effective. An oil stone Sharpening stones are used to grind and hone the edges of steel tools and implements. ...


Some naturally occurring abrasives are:

Some abrasive minerals (such as zirconia alumina) occur naturally but are sufficiently rare or sufficiently more difficult/costly to obtain such that a synthetic stone is used industrially. These and other artificial abrasives include: Doubly refracting Calcite from Iceberg claim, Dixon, New Mexico. ... Calcium carbonate is a chemical compound, with chemical formula CaCO3. ... Emery is a very hard rock type used to make abrasive powder. ... This article is about the gemstone. ... Novaculite is a form of chert or flint found in the Ouachita Mountains of Arkansas and Oklahoma and in the Marathon Uplift of Texas. ... // Specimen of highly porous pumice from Teide volcano on Tenerife, Canary Islands. ... Iron(III) oxide — also known as ferric oxide, Hematite, red iron oxide, synthetic maghemite, colcothar, or simply rust — is one of several oxide compounds of iron, and has paramagnetic properties. ... Patterns in the sand Sand is a granular material made up of fine rock particles. ... Zirconia Alumina is commonly used as a sand-blasting media. ...

Borazon is the third hardest substance that is artificially produced, preceded by aggregated diamond nanorods and man-made diamonds, respectively. ... Boron nitride is a binary chemical compound, consisting of equal proportions of boron and nitrogen, with formula BN. Structurally, it is isoelectronic to carbon and takes on similar physical forms: a hexagonal, graphite-like one, and a cubic, diamond-like one. ... Fixed Partial Denture, or Bridge The word ceramic is derived from the Greek word κεραμικός (keramikos). ... Corundum (from Tamil kurundam) is a crystalline form of aluminium oxide and one of the rock-forming minerals. ... Aluminium oxide is a chemical compound of aluminium and oxygen with the chemical formula Al2O3. ... Dry ice is a genericized trademark for solid (frozen) carbon dioxide. ... This article needs additional references or sources for verification. ... Silicon carbide (SiC) is a ceramic compound of silicon and carbon that is manufactured on a large scale for use mainly as an abrasive but also occurs in nature as the extremely rare mineral moissanite. ...

Manufactured abrasives

Abrasives are shaped for various purposes. Natural abrasives are often sold as dressed stones, usually in the from of a rectangular block. Both natural and synthetic abrasives are commonly available in a wide variety of shapes, often coming as bonded or coated abrasives, including blocks, belts, discs, wheels, sheets, rods and loose grains.


Bonded abrasives

Assorted grinding wheels as examples of bonded abrasives.
A grinding wheel with a reservoir to hold water as a lubricant and coolant.
A grinding wheel with a reservoir to hold water as a lubricant and coolant.

A bonded abrasive is composed of an abrasive material contained within a matrix, although very fine aluminium oxide abrasive may comprise sintered material. This matrix is called a binder and is often a clay, a resin, a glass or a rubber. This mixture of binder and abrasive is typically shaped into blocks, sticks, or wheels. The most usual abrasive used is aluminium oxide. Also common are silicon carbide, tungsten carbide and garnet. Artificial sharpening stones are often a bonded abrasive and are readily available as a two sided block, each side being a different grade of grit. Image File history File linksMetadata Size of this preview: 800 × 600 pixelsFull resolution (1600 × 1200 pixel, file size: 386 KB, MIME type: image/jpeg) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Abrasive Metadata This file contains additional... Image File history File linksMetadata Size of this preview: 800 × 600 pixelsFull resolution (1600 × 1200 pixel, file size: 386 KB, MIME type: image/jpeg) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Abrasive Metadata This file contains additional... Image File history File linksMetadata Download high-resolution version (1358x1650, 441 KB) de: Schleifstein im Freilichtmuseum Neuhausen ob Eck Recorded by Flominator on July 19, 2005 Use of pictures approved by director Walter Knittel via e-mail File links The following pages on the English Wikipedia link to this file... Image File history File linksMetadata Download high-resolution version (1358x1650, 441 KB) de: Schleifstein im Freilichtmuseum Neuhausen ob Eck Recorded by Flominator on July 19, 2005 Use of pictures approved by director Walter Knittel via e-mail File links The following pages on the English Wikipedia link to this file... The matrix or groundmass of an igneous rock consists of fine grained often microscopic crystals in which larger crystals (phenocrysts) are embedded. ... Sintering is a method for making objects from powder, increasing the adhesion between particles as they are heated. ... The Gay Head cliffs in Marthas Vineyard are made almost entirely of clay. ... Insect trapped in resin. ... This article needs additional references or sources for verification. ... This does not cite any references or sources. ... Aluminium oxide is a chemical compound of aluminium and oxygen with the chemical formula Al2O3. ... Silicon carbide (SiC) is a ceramic compound of silicon and carbon that is manufactured on a large scale for use mainly as an abrasive but also occurs in nature as the extremely rare mineral moissanite. ... Monotungsten carbide, WC, or Ditungsten Carbide, W2C, is a chemical compound containing tungsten and carbon, similar to titanium carbide. ... Garnet is a group of minerals that have been used since the Bronze Age as gemstones and abrasives. ... An oil stone Sharpening stones are used to grind and hone the edges of steel tools and implements. ... Look up grit, GRIT, grits, GRITS in Wiktionary, the free dictionary. ...


Grinding wheels are cylinders that are rotated at high speed. While once worked with a foot pedal or hand crank, the introduction of electric motors has made it necessary to construct the wheel to withstand greater radial stress to prevent the wheel flying apart as it spins. Similar issues arise with cutting wheels which are often structurally reinforced with impregnated fibres. High relative speed between abrasive and workpiece often makes necessary the use of a lubricant of some kind. Traditionally they were called coolants as they were used to prevent frictional heat build up which could damage the workpiece (such as ruining the temper of a blade). Some research suggests that the heat transport property of a lubricant is less important when dealing with metals as the metal will quickly conduct heat from the work surface. More important are their effects upon lessening tensile stresses while increasing some compressive stresses and reducing "thermal and mechanical stresses during chip formation". [2] Grinding wheel A grinding wheel is an expendable wheel that carries an abrasive compound on its periphery. ... Grinding wheel A grinding wheel is an expendable wheel that carries an abrasive compound on its periphery. ... A coolant, or heat transfer fluid, is a fluid which flows through a device in order to prevent its overheating, transferring the heat produced by the device to other devices that utilize or dissipate it. ... Tempering is a heat treatment technique for metals and alloys. ...


Various shapes are also used as heads on rotary tools used in precision work, such as scale modelling. A handheld power tool with a variety of rotating accessory bits and attachments that can be used for cutting, carving, sanding, polishing and many other applications. ... A scale model of the Tower of London. ...


Bonded abrasives need to be trued and dressed after they are used. Dressing is cleaning the waste material (swarf and loose abrasive) from the surface and exposing fresh grit. Depending upon the abrasive and how it was used, dressing may involve the abrasive being simply placed under running water and brushed with a stiff brush for a soft stone or the abrasive being ground against another abrasive, such as aluminium oxide used to dress a grinding wheel.


Truing is restoring the abrasive to its original surface shape. Wheels and stones tend to wear unevenly, leaving the cutting surface no longer flat (said to be "dished out" if it is meant to be a flat stone) or no longer the same diameter across the cutting face. This will lead to uneven abrasion and other difficulties.


Coated abrasives

A German sandpaper showing its backing and FEPA grit size.
A German sandpaper showing its backing and FEPA grit size.
Main article: Coated abrasive

A coated abrasive comprises an abrasive fixed to a backing material such as paper, cloth, rubber, resin, polyester or even metal, many of which are flexible. Sandpaper is a very common coated abrasive. Coated abrasives are commonly the same minerals as are used for bonded abrasives. A bonding agent (often some sort of adhesive or resin) is applied to the backing to provide a flat surface to which the grit is then subsequently adhered. A woven backing may also use a filler agent (again, often a resin) to provide additional resilience. Image File history File linksMetadata Size of this preview: 721 × 600 pixelsFull resolution (1308 × 1088 pixel, file size: 174 KB, MIME type: image/jpeg) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Abrasive Metadata This file contains additional... Image File history File linksMetadata Size of this preview: 721 × 600 pixelsFull resolution (1308 × 1088 pixel, file size: 174 KB, MIME type: image/jpeg) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Abrasive Metadata This file contains additional... Look up grit, GRIT, grits, GRITS in Wiktionary, the free dictionary. ... Coated abrasives are made of abrasive grains adhered to the surface of flexible or semi-flexible backings such as paper, cloth, vulcanized fiber, plastic films. ...


Coated abrasives may be shaped for use in rotary and orbital sanders, for wrapping around sanding blocks, as handpads, as closed loops for use on belt grinders, as striking surfaces on matchtboxes, on diamond plates and diamond steels. Diamond tools, though for cutting, are often abrasive in nature.


Other abrasives and their uses

Here the abrasiveness of toothpaste is detailed by its Relative Dentin Abrasivity (RDA)
Here the abrasiveness of toothpaste is detailed by its Relative Dentin Abrasivity (RDA)

Sand, glass beads, metal pellets and dry ice may all be used for a process called sandblasting (or similar, such as the use of glass beads which is "bead blasting"). Dry ice will sublimate meaning that there is no residual abrasive left afterwards. Image File history File links Size of this preview: 800 × 533 pixelsFull resolution (892 × 594 pixel, file size: 50 KB, MIME type: image/jpeg) Abrasiveness of toothpaste is measured by its Relative Dentin Abrasivity (RDA). ... Image File history File links Size of this preview: 800 × 533 pixelsFull resolution (892 × 594 pixel, file size: 50 KB, MIME type: image/jpeg) Abrasiveness of toothpaste is measured by its Relative Dentin Abrasivity (RDA). ... Parts of a tooth, including dentin Dentin (BE: dentine) is the substance between enamel (substance in the crown) or cementum (substance in the root) of a tooth and the pulp chamber. ...


Cutting compound used on automotive paint is an example of an abrasive suspended in a liquid, paste or wax, as are some polishing liquids for silverware and optical media. The liquid, paste or wax acts as a binding agent that keeps the abrasive attached to the cloth which is used to as a backing to move the abrasive across the workpiece. On cars in particular, wax may serve as both a protective agent by preventing exposure of the paint of metal to air and also act as an optical filler to make scratches less noticeable. Toothpaste contains calcium carbonate]] or silica as a "polishing agent" to remove plaque and other matter from teeth as the Mohs scale of mineral hardness|hardness of calcium carbonate is less than that of tooth enamel but more than that of the contaminating agent.


Very fine Iron(III) oxide|rouge powder was commonly used for grinding glass, being somewhat replaced by modern ceramics, and is still used in jewelery making for a highly reflective finish.


Cleaning products may also contain abrasives suspended in a paste or cream. They are chosen to be reasonably safe on some linoleum, tile, metal or stone surfaces. However, many laminate surfaces and ceramic topped stoves are easily damaged by these abrasive compounds. Even ceramic/pottery tableware or cookware can damage these surfaces, particularly the bottom of the tableware which is often unglazed in part or in whole and acts as simply another bonded abrasive.[3]


Metal pots and stoves are often scoured with abrasive cleaners, typically in the form of the aforementioned cream or paste or of steel wool.


Human skin is also subjected to abrasion in the form of exfoliation. Abrasives for this can be much softer and more exotic than for other purposes and may include things like almond and oatmeal.[4] Dermabrasion and microdermabrasion are now rather commonplace cosmetic procedures which use mineral abrasives.


Scratched compact discs and DVDs may sometimes be repaired through buffing with a very fine compound, the principle being that a multitude of small scratches will be more optically transparent than a single large scratch. However, this does take some skill and will eventually cause the protective coating of the disc to be entirely eroded (especially if the original scratch is deep), after which the data surface will be destroyed if abrasion continues.


Choice of abrasive

The shape, size and nature of the workpiece and the desired finish will influence the choice of the abrasive used. A bonded abrasive grind wheel may be used to commercially sharpen a knife (producing a hollow grind), but an individual may then sharpen the same knife with a natural sharpening stone or an even flexible coated abrasive (like a sandpaper) stuck to a soft, non-slip surface to make achieving a convex grind easier. Similarly, a brass mirror may be cut with a bonded abrasive, have its surface flattened with a coated abrasive to achieve a basic shape, and then have finer grades of abrasive successively appied culminating in a wax paste impregnated with rouge to leave a sort of "grainless finish" called, in this case, a "mirror finish". Types of grind: a)axe b)saber c)flat d)hollow e)chisel The grind of an edge refers to the angle and curvature of that blades cross section. ... Types of grind: a)axe b)saber c)flat d)hollow e)chisel The grind of an edge refers to the angle and curvature of that blades cross section. ...


Also, different shapes of adhesive may make it harder to abrade certain areas of the workpiece. Health hazards can arise from any dust produced (which may be ameliorated through the use of a lubricant) which could lead to silicosis (when the abrasive or workpiece is a silicate) and the choice of any lubricant. Besides water, oils are the most common lubricants. These may present inhalation hazards, contact hazards and, as friction necessarily produces heat, flammable material hazards.[5] Silicosis (also known as Grinders disease) is a form of pneumoconiosis caused by inhalation of crystalline silica dust, and is marked by inflammation and scarring in forms of nodular lesions in the upper lobes of the lungs. ... In chemistry, a silicate is a compound containing an anion in which one or more central silicon atoms are surrounded by electronegative ligands. ...


An abrasive which is too hard or too coarse can remove too much material or leave undesired scratch marks. Besides being unsightly, scratching can have other, more serious effects. Excessive abrasion or the presence of scratches may:

  • diminish or destroy usefulness (as in the case of scratched optics and compact discs or a dull knife);
  • trap dirt, water, or other material;
  • increase surface area (permitting greater chemical reactivity such as increased rusting which is also affected by matter caught in scratches);
  • erode or penetrate a coating (such as a paint or a chemical or wear resistant coating);
  • overly quickly cause an object to wear away (such as a blade or a gemstone);
  • increase friction (as in jeweled bearings and pistons).

A finer or softer abrasive will tend to leave much finer scratch marks which may even be invisible to the naked eye (a "grainless finish"); a softer abrasive may not even significantly abrade a certain object. A softer or finer abrasive will take longer to cut as tends to cut less deeply than a coarser, harder material. Also, the softer abrasive may become less effective more quickly as the abrasive is itself abraded. This allows fine abrasives to be used in the polishing of metal and lenses where the series of increasingly fine scratches tends to take on a much more shiny or reflective appearance or greater transparency. Very fine abrasives may be used to coat the strop for a cut-throat razors, however, the purpose of stropping is not to abrade material but to straighten the burr on an edge. The final stage of sharpening Japanese swords called polishing and may be a form of superfinishing. For the book by Sir Isaac Newton, see Opticks. ... A Compact Disc or CD is an optical disc used to store digital data, originally developed for storing digital audio. ... A knife is a sharp-edged (single or double edged) instrument consisting of a thin blade used for cutting and fitted with a handle. ... Reactivity refers to the rate at which a chemical substance tends to undergo a chemical reaction in time. ... A blacksmith removing rust with sand prior to welding Rust damage in automobiles can create hidden dangers. ... ruby jewel bearings used in an Omega mechanical watch movement A jewel bearing is a bearing which allows motion by running a shaft slightly off-center so that the shaft rolls inside of the bearing rather than sliding. ... For the use of the term in optics, see piston (optics). ... A lens. ... See: transparency (optics) alpha compositing GIF#Transparency transparency (overhead projector) market transparency transparency (telecommunication) transparency (computing) For X11 pseudo-transparency, see pseudo-transparency. ... Wiktionary has a definition of: Strop A strop is a flexible strip of leather or canvas used for sharpening a razor. ... Collection of Modern Safety Razors - Gillette Fusion Power, Gillette M3Power, Mach3 Turbo Champion, Schick Quattro Chrome, Schick Quattro Power, Gillette Mach3, Gillette Sensor, Schick Xtreme3, Schick Xtreme SubZero, and Schick Xtreme3 Disposables A razor is an edge tool primarily used in shaving. ... Katana of the 16th or 17th Century, with its saya. ... Superfinishing is a metalworking process which produces a very fine, mirror-smooth finish. ...


Different chemical or structural modifications may be made to alter the cutting properties of the abrasive.[6]


Other very important considerations are price and availability. Diamond, for a long time considered the hardest substance in existence, is actually softer than fullerite and even harder aggregated diamond nanorods, both of which have been synthesised in laboratories but no commercial process has yet been developed. Diamond itself is expensive due to scarcity in nature and the cost of synthesising it. Bauxite is a very common ore which, along with corundum's reasonably high hardness, contributes to corundum's status as a common, inexpensive abrasive. The C60 fullerene in crystalline form Fullerites are the solid-state manifestation of fullerenes and related compounds and materials. ... Aggregated diamond nanorods, or ADNRs, are an allotrope of carbon believed to be the hardest and least compressible known material, as measured by its isothermal bulk modulus; aggregated diamond nanorods have a modulus of 491 gigapascals (GPa), while a conventional diamond has a modulus of 442 GPa. ... Iron ore (Banded iron formation) Manganese ore Lead ore Gold ore An ore is a volume of rock containing components or minerals in a mode of occurrence which renders it valuable for mining. ...


Thought must be given to the desired task about using an appropriately hard abrasive. At one end, using an excessively hard abrasive wastes money by wearing it down when a cheaper, less hard abrasive would suffice. At the other end, if too soft, abrasion does not take place in a timely fashion, effectively wasting the abrasive as well as any accruing costs associated with loss of time.


Other instances of abrasion

Aside from the aforementioned uses of shaping and finishing, abrasives may also be used to prepare surfaces for application of some sort of paint of adhesive. An excessively smooth surface may prevent paint and adhesives from adhering as strongly as an irregular surface could allow. Inflatable tyre repair kits (which, on bicycles particularly, are actually patches for the inner tube rather than the tyre) require use of an abrasive so that the self-vulcanising cement will stick strongly. An adhesive is a compound that adheres or bonds two items together. ... For a table of tire companies, see List of tire companies. ... Firestone tire A tire (US spelling) or tyre (UK spelling) is a roughly toroidal piece of (usually) rubber placed on a wheel to cushion it. ... Vulcanization is the process of cross-linking elastomer molecules to make the bulk material harder, less soluble and more durable. ... In the most general sense of the word, cement is a binder, a substance which sets and hardens independently, and can bind other materials together. ...


Inadvertently, people who use knives on glass or metal cutting boards are abrading their knife blades. The pressure at the knife edge can easily create microscopic (or even macroscopic) cuts in the board. This cut is a ready source of abrasive material as well as a channel full of this abrasive through which the edge slides. For this reason—without regard for the health benefits—wooden boards are much more desirable. A similar occurrence arises with glass-cutters. Glass-cutters are have circular blades that are designed to roll not slide. They should never retrace an already effected cut. A wooden chopping board with a chefs knife. ... glass cutter, showing hardened steel cutting wheel (far left), notches for snapping, and ball (on end of handle) for tapping A glass cutter is a hand tool which aids in the cutting (strictly, the controlled breaking) of flat or pane glass. ...


Undesired abrasion may result from the presence of carbon in internal combustion engines. While smaller particles are readily transported by the lubrication system, larger carbon particles may abrade components with close tolerances. The carbon arises from the excessive heating of engine oil or from incomplete combustion. This soot may contain fullerenes which are noted for their extreme hardness—and small size and limited quantity which would tend to limit their effect. General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Standard atomic weight 12. ... This article does not cite any references or sources. ... It has been suggested that toleration be merged into this article or section. ... Motor oil is a type of liquid oil used for lubrication by various kinds of motors, especially internal combustion engines. ... A combustion reaction taking place in igniting a match Combustion or burning is a complex sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat or both heat and light in the form of either a glow or flames. ... Buckminsterfullerene (C60) Fullerenes are molecules composed entirely of carbon, taking the form of a hollow sphere, ellipsoid, or tube. ...


References

  1. ^ Abrasives engineering glossary. Retrieved on 2007-04-06.
  2. ^ Grinding Stresses, Grinding Wheel Institute, 1964
  3. ^ Care of laminate surface. Retrieved on 2007-04-07.
  4. ^ Nutrimetics, Honey and Almond Scrub
  5. ^ OSH Answers: Metalworking fluids. Retrieved on 2007-04-06.
  6. ^ FEPA Structure. Retrieved on 2007-04-05.
Look up abrasive in Wiktionary, the free dictionary.

Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... is the 96th day of the year (97th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... April 7 is the 97th day of the year in the Gregorian calendar (98th in leap years). ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... is the 96th day of the year (97th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... is the 95th day of the year (96th in leap years) in the Gregorian calendar. ... Wikipedia does not have an article with this exact name. ... Wiktionary (a portmanteau of wiki and dictionary) is a multilingual, Web-based project to create a free content dictionary, available in over 150 languages. ...

External link

  • Comet Abrasifs & Sciage
  • Dettinger France

  Results from FactBites:
 
Abrasive - Wikipedia, the free encyclopedia (144 words)
An abrasive is usually a material that is used to smooth, machine, or, in some cases, roughen another softer material through extensive rubbing.
Abrasives are used to remove surface materials such as metal, ceramics, glass, plastics, and paint.
Some abrasives are designed for use on bench or back stand grinders, while others are designed for use on portable or handheld grinders or sanders.
abrasive - Columbia Encyclopedia article about abrasive (375 words)
Natural abrasives include sand sand, rock material occurring in the form of loose, rounded or angular grains, varying in size from.06 mm to 2 mm in diameter, the particles being smaller than those of gravel and larger than those of silt or clay.
Usually found at the surface of a lava flow, it is colorless or light gray and has the general appearance of a rock froth.
The hardest abrasives are natural or synthetic diamonds diamond, mineral, one of two crystalline forms of the element carbon (see allotropy), the hardest natural substance known, used as a gem and in industry.
  More results at FactBites »

 
 

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