Grinding & Cutoff Wheels
Grinding wheels are used for stock removal, grinding, cutting, blending, finishing, repairing, and sharpening. Wheel attachment type can be either arbor or quick change. Grinding wheels are formed with a bonding agent that holds abrasive particles in place. Bond type can be vitrified, silicate, resinoid, rubber, shellac, oxychloride, or metal. Wheels that are designated as reinforced have an added filament for additional strength. Wheel shape is standardized and uses a numbering system of 1 to 50. The most common shapes are as follows:
Type 1 - Straight Wheel
Type 2 - Cylindrical Wheel
Type 5 - One Side Recessed
Type 6 - Straight Cup
Type 7 - Two Sides Recessed
Type 11 - Flared Cup
Type 12 - Dish Wheel
Type 20 - One Side Concaved
Type 27 - Depressed Center Wheel
Type 28 - Depressed Center Wheel (Concave)
Type 29 - Depressed Center Wheel (Convex)
Type 35 - Plate Mounted Disc
Type 50 - Plate Mounted Wheel
Wheel hardness is rated from A to Z, with Z being the hardest. Higher ratings result in longer wheel life, but cutting rate is decreased. Therefore a lower rating is best for grinding harder materials, while softer materials can be worked with a higher-rated wheel. Common abrasive materials include aluminum oxide, ceramic, alumina zirconia, silicon carbide, CBN, and diamond. Abrasive grades and grits range from very coarse to ultrafine.
