Image Credit: Flexovit USA, Inc. | Norton Abrasives | Abtex Corporation 

Flap wheels and specialty abrasives include cartridge rolls, cross pads, drum sleeves and flap discs made from coated or nonwoven abrasives. This product category also includes convolute, laminated cotton, and unified wheels. Cartridge rolls, cross pads and drum sleeves are used to sand, grind, debur or finish smaller, hard-to-reach bores, cavities or recesses. Flap wheels and flap discs are suitable for long-term use because new grains are exposed as products wear down. Abrasive flaps radiate out from the center of the wheel where the flaps are bonded together. Non-woven discs and convolute, laminated cotton, and unified wheels are used extensively in industrial deburring and finishing applications. Important specifications for flap wheels and specialty abrasives include outer diameter (OD), shank diameter, and bore diameter. Bore is the inner diameter (ID) of a center-mounted abrasive product. Shank diameter measures the diameter of an integral shank, pin, shaft or mandrel on mounted points or wheels.

Abrasive Materials

   
Flap wheels and specialty abrasives use several types of abrasive grains. Aluminum oxide 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 used typically 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. Other types of abrasive grains include garnet, a natural silicate material, and aggregates of mixed particles that are formed to a uniform size. Cork is typically used in glass finishing because it allows abrasive products to improve surface finish quality.

Available Options

    
Flap wheels and specialty abrasives differ in terms of grit sizes, backing types, and mounting styles. Grit sizes are based on ANSI (U.S.), FEPA (European), JIS (Japanese), and Micron graded standards. Grading systems define grit sizes through specified upper and lower limits at specific points in the size distribution. Backing types for flap wheels and specialty abrasives include cloth, fiber, plastic film, foam or sponge, paper, and metal. Open mesh woven fabric screens and combinations of backing materials are also available. In terms of mounting styles, some flap wheels and specialty abrasives attach to a backup pad or holder with a hook and loop fabric. Other products provide a central hole or bore for mandrel, arbor, spindle, or shaft mounting. Pressure sensitive adhesives (PSAs) and quick-change products are also available.

How to Select

   
Selecting flap wheels and specialty abrasives require an analysis of features. Some products provide an open coat. Others use a closed coat. Lubricated abrasive products provide improved life and resistance to loading on paint, wood plastic or composite sanding applications. Anti-static products reduce or eliminate static charge generation, an important feature in some wood sanding applications. Engineered and structured products are also available. Grinding aids enhance cutting performance on stainless steel, nickel alloys and titanium. In coated abrasive belts or discs, grinding aids are added in the form of a supersize top layer.

Related Standards

• A-A-58054 - ABRASIVE MATS, NON-WOVEN, NON-METALLIC
• ANSI B74.10 - SPECIFICATIONS FOR GRADING OF ABRASIVE MICROGRITS
• ASME B5.35 - MACHINE MOUNTING FOR ABRASIVE DISCS AND PLATE MOUNTED WHEELS