A combination of these methods is sometimes used to produce products for specific applications. The size coat is the bonding system which anchors the abrasives firmly to the backing. This coat determines the final strength or flexibility of the product Glue bonds are made from animal hides and are used for both the maker and the size coat. Resin Over Glue Bond means a resin size coat is put over a glue maker coat. This gives an intermediate action somewhere between a straight glue bond and a straight resin bond.
Abrasives are the cutting tools on the surface of the and can be either man-made or natural.
Some abrasives must be tough and durable to resist point wear or fracture for high pressure applications while others must be mild and friable to fracture before serious dulling occurs. Aluminum Oxide is a tough, wedge-shaped abrasive that is well suited to grinding most steels, tough bronze and hard woods. Ceramic Aluminum Oxide is the newest in the family of man-made abrasives. Natural abrasives are generally soft and more suited for mild action and fine finish work. For coated abrasives, Garnet is the most widely used of all the natural abrasives.