The ability of the abrasive grain to penetrate the article being abraded depends to a large extent upon the hardness, toughness and shape of the abrasive. The types of abrasives used in order of hardness are Silicon Carbide, Alumina Zirconia, Premium Aluminum Oxide, White Aluminum Oxide, Brown Aluminum Oxide and Emery.

SILICON CARBIDE This mineral is synthetically produced in electric furnaces to produce a glossy black color and a high degree of hardness. Due to its brittle characteristics it fractures into sharp sliver-like wedges having cutting edges that permit rapid stock removal. Recommended for finishing nonferrous metals such as brass, bronze, copper and aluminum; and other materials such as leather, glass, wood, rubber and plastic. It is also used to finish and polish automotive primers, lacquers and sealers in general.

ALUMINA ZIRCONIA This mineral is a mixture of Zirconium Oxide dissolved in Aluminum Oxide at molten temperatures. Coated abrasives use a micro-crystalline structure form of this mineral that is characterized as sharp, hard and extremely tough. Because of the structure and extreme toughness, smaller particles of grain break off in use and at a much slower rate than standard aluminum oxide. It produces superior performance on a wide variety of materials of both high and low tensile strength under high grinding pressures. Typical applications include grinding of carbon steel, stainless steel, tough bronzes, a wide variety of stainless steel and exotic alloys, grey malleable, ductile and nodular cast iron, aluminum, titanium, etc. Alumina Zirconia is excellent on high grinding pressure applications and very often it is equally effective at lower grinding pressure levels also.

PREMIUM ALUMINUM OXIDE This is a synthetic mineral that begins as fused Aluminum Oxide of high purity and is treated at very high temperatures to improve its hardness and friability properties. With these improvements, the grains maintain a sharp cutting edge that cuts cooler, resulting in longer life and lower grinding costs. It is used for grinding high tensile strength materials such as steel, stainless steel and tough bronzes. It is also very effective for rough grinding of many low tensile strength materials such as grey iron, low carbon steel, aluminum, and brasses when heavier grinding pressures are used resulting in longer life and lower grinding costs.

WHITE ALUMINUM OXIDE White Aluminum Oxide is a durable manufactured abrasive which is characterized by long life of its cutting edges. It is recommended for sanding of all types of wood.

BROWN ALUMINUM OXIDE This mineral has a grain with a large crystal size in its structure. It is characterized as sharp, hard, and tough. It is used for grinding and polishing high tensile strength materials such as steel, stainless steel, tough bronzes, etc. It is also very effective for rough grinding of many low tensile strength materials such as grey cast iron, aluminum, brass, etc. when heavier grinding pressures are used.

EMERY Man-made emery is a regular aluminum oxide containing a small amount of ferric oxide. This addition gives high durability. Emery is recommended for hand polishing of ferrous and nonferrous materials.

Cloth, resin fiber, paper, and a combination of these materials are the most popular backings used in the manufacturing of coated abrasives.

CLOTH includes "J", "X", and "Y" weights. "J" weight (jeans) cloth is used for polishing and finishing operations or where flexible products are required. "X" weight (drills) is a heavier, stronger and less flexible material that is used in heavy and medium duty operations. "Y" weight (sateen) is an extra heavy backing for heavy duty grinding.

RESIN FIBER backings consist of multiple bonded layers of impregnated paper. They are tough and strong for disc uses.

PAPER is used in "A", "C", "D", "E", and "F" weights. "A" weight is light and flexible. "C" and "D" weights are stronger and less flexible. "E" and "F" weights are still stronger mostly for rolls, belts, and discs where high resistance to tearing is required.

COMBINATION backing is a result of laminating "E" weight paper and light cloth. This is primarily for disc and drum sanding.

The primary forms of coated abrasives are: Sheets, Discs, Rolls, Belts, PSA (Pressure sensitive adhesives) discs, flap wheels, bodyfiles, specialties and non-woven.

Sheets
9" x 11" sheets are for manual or belt sander use. Employed in handcrafting, inaccessible or inadequate parts for mechanical applications.

Rolls
Abrasive rolls presented in diverse widths rangin from 3/8" up to 55" and in lengths ranging from 10 yds to 100 yds. Used in diverse machinery and manually applications.

Discs
Resin fiber discs: We carry a line of RFD ranging from 4" in diameter to 9 1/8", either in premium aluminum oxide or alumina zirconia coating.

Paper and cloth discs
Both aluminum oxide and silicon carbide are used with PSA (pressure sensitive adhesive) or Kwik-Grip, some are coated with Zinc steareate (only paper) to avoid premature loading, some are completely waterproof. These discs are presented in diameters ranging 3" to 24". The basic applications are in the automotive and wood industries used with orbital sanders.

Quick change discs
Presented both in resin fiber and poly-cotton cloth, both basically in premium aluminum oxide. Ranging from 1" to 3" in diameter, twist and lock assembly standard (other assembly types available). Portable motor tools required.

Belts
Abrasive segments powerfully joined at one end in different angles. Ranging from 1/4" to 55" in width, and from 8" to 13 yds in length. Used in mechanical sanders, fixed or portable, as big as those in the stainless steel or wood industries or small as the ones used in different types of shops. It is the abrasive tool mostly used in industries worldwide.

Flap wheels -- 4" to 8"
Used in sanding and finishing of flat or curved surfaces, small parts or cavities. Their diameters range form 1" to 8". Used in industrial applications of stainless steel, metal &automotive, among others.

Specialties
Personalized to the industrial application required. A great variety of forms and sizes designed with the purpose of adding productivity within the process of our customers, with the use of portable sanding machinery. Some of the most popular items are stars, cartridges and spiral belts.

Body file sheets
In different standard sizes, presented for economy and high performance operations in the automotive industry. Available in stearated premium aluminum oxide with velour and PSA backings.

Nonwoven
Nonwoven textiles coated with abrasives. Presented in pads, belts and discs. Their basic use is for surface preparation as well as finishing.

Identifying the size of the grit to be used is very important, especially considering the large variety of grades available.

The following table compares the ANSI (American National Standards Institute) norm B74.18-1984, FEPA "P" (European Federation of Abrasives Producers) and JIS (Japanese International Standard) regulation. These three standards are compared with the average size of the particles in microns and with a simplified grading pattern (that meet two or more grits in one value).

This chart shows the five basic types of operations with its corresponding grade: Grading Systems Table