Monthly Archives: July 2019

Types of Grains Used as Abrasives in Grinding Wheels

Types of Grains Used as Abrasives in Grinding Wheels

The grinding wheel is a cutting & polishing abrasive tool. In a grinding wheel, the abrasive acts in the same fashion as a tooth acts in a saw except that the grinding wheel has the grains distributed throughout the wheel and not just in one direction. It takes millions of grain particles to form an abrasive which is then used to act against the work piece and cut or polish or shape the material. They are most commonly found in applications such as cutting & polishing tiles, metals, wood, ceramic & concrete and many other materials. While grinding wheels are highly efficient, choosing the wrong abrasive can bring irreversible harm to the work piece. Here’s an insight into choosing the right grains for your task with reference to Cumi Abrasives - the pioneers of Coated Abrasives, Bonded Abrasives, Nonwoven, Metalworking fluids and Power Tools in India. With extensive experience in the industrial tool supply business, MK Industrial suppliers are the leading suppliers of Cumi Products in India.

  1. Aluminum Oxide:
    This material is known for its hardness and strength at a lesser cost as compared to other abrasive types. It is mostly used on metal or wood. Its low heat retention and low specific heat make it suitable for a wide array of grinding and sanding applications. It is used to remove minor welds and imperfections along with removing light stock, blending and finishing. It is used by carpenters on log furniture and other woods. In metals, they are mostly used on light ones such as alloy steel and aluminum. Aluminum Oxide is available in grits 24-600.
  1. Zirconia Alumina:
    A bluish-green colored element also referred to as Zinc or Zirconium, it is perfect for coarse to medium grit applications on metal. Works best under high pressure such as stock removal on Chrome and chrome-nickel steel or high-alloy steel, which is required for the grain to fracture exposing new sharp edges. It has large fracture planes which self-sharpens as it cuts. It is employed for applications such as blending, deburring and weld removal. It can have a life span twice to that of an aluminum oxide disc when used in the proper application. Zirconia Alumina is available in grits 24-180.
  1. Ceramic Alumina:
    Ceramic abrasives are long life & come with the fastest cutting rate of all coated abrasives. In terms of chronology, they are the youngest and the newest being a result of research and development. Hence, they possess better performance, are aggressive and provide a consistent cut under moderate to high pressure. It is a premium level abrasive for high heat generating applications such as stainless steel. The cool cutting technology for reducing heat and increasing performance is ideal for grinding and blending welds. Ceramic is available in grits 24-120.
  1. Silicon Carbide:
    Black in color, Silicon Carbide is a hard and sharp synthetic abrasive. Silicon Carbide grains have traditionally been used for gemstone cutting and a standard for cabochon cutting. They are ideal for wet sanding, grinding and polishing gemstones. They have an excellent record on titanium, fiberglass, plastics, tile and masonry products. Silicon carbide abrasive grains are sharp enough to quickly remove any coatings such as adhesives, paint, acrylics, mastics, etc. Aggressive cutting action provides a clean, smooth finish on concrete, marble, granite, and other stonework.
  1. Crocus
    Crocus, made from iron oxide, is reddish-brown in color and is used for ultra-fine polishing & cleaning of metals such as Gold. It is also used for light abrasion on metal surfaces such as camshafts, rotors, points, etc.
  1. Emery
    It is brownish-black or dark gray in color and also happens to be the hardest mineral after diamond, making it the second hardest mineral. It is used more for cleaning and polishing and less for cutting. Unlike other abrasive materials, emery grains have more than one sharp edge on each particle. Hence, making them use more than once in a sandblasting operation. Understanding grinding wheel fundamentals can help you find the right wheel for the right job!