ALUMINUM OXIDE – is a tough and durable man-made abrasive characterized by the long life and wear resistance of its cutting edges. It offers enormous penetrating strength, even at high speeds. Applications: ferrous metals • hardwood • aluminum
CERAMIC – is a synthetic, white, abrasive grain formulated to withstand high pressure and extreme heat associated with grinding. Its crystalline structure continually provides self-sharpening grain for aggressive cut and stock removal. Applications: Metalworking • Excels on grinding stainless steel, titanium and super alloys • Used for moderate and high-pressure applications • offhand, through feed and power assist applications
SILICON CARBIDE – is the hardest and sharpest of the manufactured abrasives. Because of its extreme sharpness, this bluish-black abrasive grain permits fast stock removal and cool cut.
Applications: non-ferrous metals i.e. brass, aluminum, and bronze • non metallics, i.e., glass, rubber, plastic, and stone • final finish on wood and stainless steel • abrasive planing particle board • cast iron • fiberglass
ZIRCONIA ALUMINA – is an ultra-tough synthetic abrasive, which provides a free, cool cut for high stock removal applications. It is tougher but sharper than aluminum oxide. It has a micro-crystalline structure which allows for controlled breakdown and self-sharpening. This bluish gray abrasive is available in coarse (24-120) grits only.
Applications: heavy duty snagging and grinding all ferrous and non-ferrous metals • abrasive planing of wood, plywood and particle board • grinding fiberglass, rubber and plastics
GARNET – is reddish brown in color. This natural abrasive is medium hard and relatively sharp but not as durable as man-made (synthetic) abrasives.
Applications: For use on wood only • particularly good for soft sappy woods such as pine •produces an excellent finish
EMERY – is a dark gray round shaped grain which tends to polish rather than abrade a worksurface.
Application: for polishing and cleaning metal only
CROCUS – Iron Oxide is a very soft natural abrasive, which is red in color.
Application: for fine polishing soft metals such as gold.
OPEN COAT – refers to coating in which 50% to 75% of the backing is covered by abrasive grain. There are voids between particles of grain, which help reduce the effect of loading caused by sawdust or metal particles. Suitable for wood and plastic.
CLOSED COAT – refers to a coating in which the entire surface of the backing is covered with abrasive grain, with no voids between particles. This is by far the most general coating in use and permits the greatest degree of stock removal and longest product life. Suitable for metal and some hard woods.
Storage Conditions for Coated Abrasives
Temperature and humidity are the two most important factors influencing coated abrasive performance. Improper or inadequate storage can decrease the productive life of the coated abrasive by as much as 70%. Backings and adhesives are sensitive to climatic changes and will gain or lose moisture according to the relative humidity of their surroundings. Fluctuating climatic conditions can cause permanent damage to the adhesive bond. Excessive humidity may cause a softening of some types of adhesive bonds so that the product quickly fills and clogs or loses its grain during use. Excessive dryness may cause brittleness, reduced flexibility and distortion of product shape. Constant levels of humidity and temperature should be maintained. Stockroom temperature should be 60-80º Fahrenheit and relative humidity between 35 and 50%. Cartons should be kept away from damp or cold walls and floor where they may absorb moisture. Store coated abrasives away from heat sources – steam-heated radiators, steam pipes,hot-air inlets, heat ducts or rooms near furnaces or ovens. Belts which have been removed from the packing case should be rolled up and stood on edge on a clean shelf. Belts may be draped over a large cylinder, such as a gallon can, brake drum or flanged hanger of the type used for garden hose. NEVER hang a belt from a nail or peg – the backing will crease and the abrasive may crack.