Image Credit: Norton Abrasives

Grinding wheels are used for metal removal, dimensioning, and finishing. They consist of an integral shank, pin, shaft, or mandrel that drives a mounted wheel or blades.

Types of Grinding Wheels

There are many types of grinding wheels, some of which are numbered by the American National Standards Institute (ANSI).

• Straight wheels are simple, flat discs without any recesses, flaring or cups.
• Blank wheels can be customized for a variety of applications.
• Cone wheels feature a curved or straight edge and, optionally, a nose radius.
• Plug wheels offer a square or curved grinding end.
• Cylindrical wheels feature a length that is equal to or greater than the thickness of the wheel.
• Depressed center wheels exclude the mounting hardware from the grinding process.
• Recessed wheels on one side are known as type 5. Recessed wheels on both sides are known as type 7.
• Flaring-cup are known as type 11.
• Straight-cup are known as type 6.
• Tapered grinding wheels have a thicker cross section at the bore.
• Dish

Grinding wheels 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.
• Silicon carbide, 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. 

Specifications

Specifications and features to consider when selecting grinding wheels include:

• Grit size - 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 - Bond types include resin, plastic, rubber, shellac, silicate or oxychloride, and vitrified glass.
• Metal bond systems - Used mainly for superabrasive or tungsten carbide grit products. There are three basic types of metal bonds:
  • 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.
  • Electroplated bonds are used to produce fine grit superabrasives.
• Mounting options - Devices can be mounted with a plate, on a quill, or using a quick-change mechanism.
• Structure - Open structure abrasives feature a low concentration. Conversely, closed structure abrasives feature a high concentration
• Face type - Face types for grinding wheels include:
  • Angled or beveled face (E face) for threading or similar applications.
  • Tapered face (V, B faces) for fluting.
  • Rounded face (F face)
• Outer diameter (OD)
• Inner diameter (ID)
• Thickness
• Rotary speed 

Standards

ANSI B74.12 - SPECIFICATION FOR THE SIZE OF ABRASIVE GRAIN - GRINDING WHEELS, POLISHING AND GENERAL INDUSTRIAL USES