A coated abrasive is a product that consists of a thin layer of abrasive grain attached to a substrate such as paper, cloth, etc. Coated abrasives come in a variety of forms such as sheets, discs, rolls, specialties, or belts.

Coated abrasives are manufactured using abrasive grains, the most common being aluminum oxide, zirconium, ceramic, silicon carbide. The crude grains are crushed and separated into sizes, called grit sizes, using calibrated screens. Grits range from 12 (very coarse) to 1200 (very fine.) Once the grains are separated into sizes, they are attached to a backing material using various bond techniques.

Aluminum Oxide:

A tough, blocky shaped, man-made grain used for high speed grinding and finishing of metals, wood, and other high tensile strength materials without excessive fracturing or shedding. Wherever the ability to resist fracturing is the main consideration, aluminum oxide will outperform all other coated abrasive grains.

Ceramic:

A high performance, man made abrasive material. Very uniform, high density, sub-micron crystals are extremely durable and self sharpening for longer life and cooler cut.  Excels on tough to grind materials.

Silicon Carbide:

A very hard, very sharp, man-made abrasive suited for nonferrous materials and non-metallic materials such as concrete, marble and glass. A very friable grain, silicon carbide cuts faster under light pressure than any other grain used in coated abrasives.

Zirconium:

A very fine, dense, man-made crystalline grain which can be used for aggressive stock removal.  Zirconium is a very dense material with a unique self-sharpening characteristic which gives it long life on heavy stock removal operations.

Cloth

Cloth backings are more durable than paper backings.  There are two common types of cloth backing; cotton (ie: Egyptian) and polyester. Cloth backings are identified by weight and flexibility:

"F" weight (J-Flex) 

Light and highly flexible. This lighter weight is suitable for cleaning, finishing, and polishing.

"J" weight (Jeans) 

Highly flexible and suitable for cleaning, finishing, and polishing of contour surfaces.

"X" weight (Drills) 

Medium to heavy weight for more strength and durability. Has low flexibility, suitable for grinding, deburring and finishing.

"H" weight (Heavy Duty) 

Heavier weight than "X" weight. It has low flexibility and is suitable for heavy duty grinding and deburring applications. Excellent edge stability.

Specialized technical papers are used as substrates for coated abrasives. They are identified by letters

representing weight and flexibility: "A" and "B" weights are light weight and highly flexible.  "C", "D", "F" weights are medium to heavy weight for more strength and less flexibility.

The grains are locked to the backing material using a bond technique that involves a two layer process. There are

three major types of bond techniques used in coated abrasives:

A very strong bond resistant to heat and moisture. Resin over resin bonds are durable for heavy stock removal. By

far, the most popular bonding method.

A bond that is resistant to heat. It is more aggressive than glue over glue bonds and leaves a finer finish than resin

over resin bonds.

A bond that is less durable than resin bonds, but glue over glue bonds produce a more uniform finish. Glue over

glue bonds softens under heat, thereby reducing the life of the product.

All coated abrasives are stiff and rigid after the drying and curing of the bond. To achieve the flexibility required for

the application, a mechanical flexing process is required. This process is actually a controlled cracking of the bond

in one or more directions to achieve the desired flexibility.

These terms refer to the spacing between the abrasive grains bonded to the backing.

Closed coat means the abrasive grains are adjacent to each other with no space between. The majority of

applications will benefit from closed coat material because it allows for more material removal.

Open coat means the grains are set apart from each other, achieving a surface coverage of about 60% or more. In

situations where loading is likely (soft, non- ferrous materials, painted surface, wood, etc.) open coat will resist

loading and clogging and extend the useful life of the abrasive.

Home    •    Cloth    •    Paper    •    Company Info    •    Contact us    •    SAIT Italy    •    F.A.Q.

SAIT Overseas Trading & Technical Corp.

P.O. Box 673 , Route 66 , Willimantic, CT 06226  •  Phone: (860) 456-4167  •  Fax: (860) 450-7347