Backing: the material used as the base or foundation for the abrasive grain to adhere to. 

Bond: the system used to hold the abrasive grains onto the backing. A combination of layers of adhesives. 

Butt Joint a type of joint used to make a belt. The two ends of the belt material butt up to each other and are attached with tape. 

Closed Coat the abrasive grains completely cover the coatside surface of the backing. 

Electrostatic a method of applying an electrical charge to the backing in order to consistently space the abrasive grains and to properly orient them on the backing material. The charge is the opposite of the charge naturally occurring in the abrasive grain. 

Filling (Loading) Clogging of the abrasive coat by swarf (the workpiece cuttings, dust, oil, grain particles, etc. created by abrading action). It can be reduced in many operations by using an open coat construction or a lubricant. 

Flexing controlled breaking of the continuous bonded abrasive coating with some detrimental effect on the bond or backing. This is done to create flexibility of the coated abrasive product. 

Glue an adhesive used in holding the grain to the backing. Traditionally made from animal hides. 

Gravity Coating a method of applying the abrasive grains by simply dropping them onto the backing material . This method is more inconsistent than electrostatic coating. 

Grit (Grade) The designation of size of an abrasive grain. The number is determined by the number of grains that fall through openings per linear inch in the controlled sieving screen. 

Lap Joint a type of joint used to make a belt. The two ends of the belt material overlap and are attached with adhesives. 

Make Coat the initial layer of adhesive used in making a coated abrasive product. This is the layer that the abrasive grains are imbedded into. 

Open Coat the individual grains are spaced at predetermined distances from one another (in open coat materials about 50 to 70 percent of the coated surface is covered with abrasive. 

Resin a synthetic adhesive used in holding the grain to the backing. Resins are stronger and resist moisture and heat build-up. 

"S" Joint a type of butt joint used to make a belt. The two ends of the belt material are cut in a "sine wave" pattern for more joint contact area. 

Shedding when the abrasive grains break loose and fall off of the abrasive product. Usually due to extreme pressure or a weak bond. 

Size Coat the secondary layer of adhesive used in making a coated abrasive product. This is the layer which covers the majority of the abrasive grains. 

Weight the unit of measure determined by the tensile strength of paper and cloth backings.

Paper: A,B,C,D,E,F from lightest to heaviest. Combination paper/cloth: T

Definitions and information taken in part from "Coated Abrasives-Modern Tool of Industry " by CAMI
Cloth: J,X,Y (cotton/polyester blend)