Image Credit: CS UNITEC | Lapmaster International | Norton Abrasives

Cut-off wheels and abrasive saw blades are used to cut bars, stock, pipes and other materials that are made of metal, concrete, or masonry. These center-mounted devices consist of an integral shank, pin, shaft, or mandrel that drives a mounted wheel or blades.  Some cut-off wheels are grinding wheels that consist of abrasive grains bonded together by a matrix of resins, epoxy, rubber, metal, and vitrified glass materials. Straight wheels are used in slot cutting applications and have a simple, flat disc shape without any recesses, flaring or cups. Depressed center cut-off wheels that protect mounting hardware from mechanical processes are also available. Sectioning blades consist of very thin superabrasive wheels that are used to slice boules into semiconductor wafers, dice processed wafers into integrated circuit chips or dies, cut optical components, and perform other specialized cutting operations. Saws or cut-off blades with slots are used to remove debris and improve cutting performance. 

Different Kinds of Abrasives

    
Cut-off wheels and abrasive saw blades use several types of abrasive grains. Aluminum oxide, the most common industrial mineral in use today, is used either individually or with other materials to form ceramic grains. Aluminum oxide is also combined with emery and crocus to produce abrasives suitable for finishing applications. Silicon carbine, a synthetic abrasive that is harder than aluminum oxide, is typically used with nonferrous materials such as brass, aluminum, and titanium. Alumina-zirconia grains fuse aluminum oxide and zirconium oxide and are used to improve grinding performance on materials such as stainless steel. Synthetic diamond superabrasives are used for grinding nonferrous metals, ceramics, glass, stone, and building materials. Cubic boron nitride (CBN), another type of superabrasive, provides superior grinding performance on carbon and alloy steels. CBN is second only to diamond in terms of hardness. Crushed tungsten carbide grits are used in metal-bonded products to abrade tough materials such as composites, fiberglass, reinforced plastics, and rubber. 

Grit Sizes and Bond Types

  
Cut-off wheels and abrasive saw blades differ in terms of grit sizes and bond types. Grit sizes are based on ANSI (U.S.), FEPA (European), JIS (Japanese), and Micron graded standards and describe both upper and lower limits. Bond types include resin, resinoid, and plastic bonding systems as well as products with rubber or elastomer bonds. Metal bonds between the abrasive grains and between the grains and a metal substrate are also available. Metal bond systems are used mainly for superabrasive or tungsten carbide grit products. Sintered metal bond systems are used when a thicker layer of superabrasive is required. Metal single layer (MSL) wheels consists of a specialized braze layer that forms a single layer of superabrasive and bond. Electroplated bond systems are used to produce fine grit superabrasive products. 

Applications

   
There are many applications for cut-off wheels and abrasive saw blades. Some are used in dry cutting, wet cutting, bench grinding, backstand grinding, or portable grinding operations. Others are used in the production of automotive parts, ceramics and glass, ophthalmic and optical products, plastics and composites, or semiconductors and electronics. Important considerations include rotary speed, outer diameter (OD), and bore size or shank diameter.

Related Standards

• A-A-59344 - CUTOFF MACHINE, ABRASIVE DISK, CHOP-STROKE
• SAA AS 4517.1 -BLANKS FOR SUPERABRASIVE CUTTING-OFF WHEELS PART 1: MANUALLY GUIDED CUTTING-OFF IN BUILDING AND CIVIL ENGINEERING
• AGA 6 - USE OF ABRASIVE GRAIN IN WIRE SAWING