ABRASIVES GRAINS:

ALUMINUM OXIDE - This type of abrasive grain is wedge shaped and is tough and fracture-resistant. Aluminum Oxide's toughness makes it well suited to grinding high tensile materials from metals to hard woods. Aluminum Oxide grains are available in many degrees of toughness (fracture-resistance) and can be identified by color (brown, white, pink). Recommendations on type to be used are based on the material to be worked. These grain types are the best choice for general grinding or polishing on metal and sanding of wood.

SILICON CARBIDE - This abrasive grain is dark gray to black in color and is characterized by its very hard and sharp properties. Throughout their use, these grains fracture easily for fast stock removal. Recommended for grinding and polishing materials such as glass, plastics, ceramics, stone, rubber and non-ferrous metals.

ZIRCONIA ALUMINA - These particular grains have a self-sharpening characteristic, which give them long life. The unique quality of being both tough and sharp make it ideal for heavy grinding operations on hard materials. In heavy grinding operations in grits 24-120 the unique feature of controlled fracturing make Zirconia Alumina the best choice.

GARNET - This grain is made by crushing semi-precious garnet stones. It is not as hard as the above synthetic abrasive grains, but is a very sharp abrasive and is widely used in furniture and woodworking plants. Garnet is not well suited for metal working because it dulls too fast.

EMERY - These grains are blocky in shape and have a good polishing action on most metals. Emery is used for general maintenance and polishing when stock removal is minimal. Used primarily by hand in sheets and rolls.

CROCUS - This product is essentially composed of ferrous oxide; Crocus is short-lived compared to other abrasives. It is used for polishing soft metals.

ADHESIVE BONDS:

The adhesives, which bond the abrasive grain to the backing are applied in two different layers. The first is referred to as the "maker coat", which bonds the grains to the backing. The second is the "size coat", which bonds to the maker coat and provides the final bonding of the grain.

GLUE - This bond consists of high quality animal hide glue used in both the "maker' and "size" coats. Glue bond products usually provide a better finish, but have a low resistance to heat.

RESIN/GLUE - Products with a resin "size" coat applied over a glue "maker" coat provides better heat resistance than glue and better finishes than resin.

RESIN - These products have both resin "size" and resin "maker" coats for maximum resistance to heat and grain shedding. This is the best all around and the most durable of all bonds.

WATERPROOF - Special bond modifications are made to the resin bond so that it can be used with water.

BACKINGS:

PAPER - This backing consists of highly specialized papers made to specific flexibility and strength measured in weight. "A" weight is light and flexible making it good for hand finishing operations. "C" and "D" weights are stronger and less flexible making them good for both hand sanding and on portable vibrating sanders. "E" weight paper is even stronger and less flexible. It can be used for roll, belt and disc applications where high tear resistance is required. "F" weight is used for rolls, belts and discs when applications require a stronger tear resistant backing than "E" weight.

CLOTH - Cotton cloth backing material is available in "X", "J" and "F" weights. "J" and "F" weight is a light cloth used for finishing operations and for polishing contours when surface uniformity and flexibility are more important than stock removal. "X" weight is a strong cloth backing available in a variety of flexes. It is recommended for belt, drum and disc grinding and polishing operations when stock removal is important.

POLYESTER - This particular material is naturally waterproof, tough and stretch resistant and the "Y" weight backing is designed for heavy duty grinding operations.

FIBRE - A fibre backing consists of multiple bonded layers. It is tough and strong for drum and disc use. Especially well suited for high speed disc grinding where heat can create a problem with other materials.

COMBINATION - A combination backing is made by laminating "E" weight paper with light cloth or two different types of cloth. Used for floor sanding products in very coarse grits and for segmental belts used in the board mill Industry.

NOTE: Coated abrasives are manufactured in either closed coat or open coat structure. Open coat products have less grain coverage about 50% to 70% of the backing. The open structure helps to prevent loading of the coated abrasive product being used on soft materials such as wood, aluminum etc. Some open coat products are available with a zinc stearate filler to help prevent loading. Closed coat products are designed for high stock removal operations on harder materials loading is not a problem. Usually, close coat products will produce a better more uniform finish. The grain coverage of close coat products are about 90% of the backing.