COATED ABRASIVES

Abrasive Products offers a full line of coated abrasives, often referred to as “sandpaper”. The term “coated abrasive” indicates how the abrasive is actually affixed to each product. Coated abrasives consist of a backing material – typically paper, woven cloth, cloth/paper combination, polyester film or vulcanized fibre – to which one of the abrasive grain types, listed in our abrasive grain section, is affixed. An initial ‘make’ coating of resin is applied to the backing, the chosen abrasive grain is then electro-coated onto the surface, followed by a second or ‘ size’ coating of resin to lock in the abrasive particles. Following an oven cure, the resulting material is converted into various forms, shapes and sizes of belts, rolls, discs or wheels to grind, de-burr, finish and polish products in a vast range of applications.

Not only are coated abrasives categorized by their configuration (belts, discs, sheets, wheels, stones), but also by the abrasives each contain.  Primary grains used are aluminum oxide,  silicon carbide, alumina zirconia, and ceramics.  Additionally, exotic abrasive such as industrial diamonds, are used for specific applications.

Abrasive Products has a trained expert staff who can answer your questions about our coated abrasives and how to best utilize them.  Contact Abrasive Products for more information on Coated Abrasives.

Coated Abrasives Products

  • Belts
  • Discs
  • Resin Fiber Discs
  • Flap Wheels & Discs
  • Sheets & Rolls

Abrasive Grains

  • Aluminum Oxide
    • Wedge shaped abrasive grain is tough and fracture resistant
    • Aluminum Oxide’s toughness makes it well suited to grinding high tensile materials from metals to hard woods.
    • Aluminum Oxide grains are available in many degrees of toughness (fracture-resistance) and can be identified by color (brown, white, pink).
    • These grain types are the best choice for general grinding or polishing on metal and sanding of wood.
    • Production wood sanding
    • Non-ferrous metal finishing
    • Ferrous metals
    • Aluminum
    • General Wood sanding
  • Silicon Carbide
    • Dark gray to black in color abrasive grain characterized by its very hard and sharp properties.
    • Throughout their use, silicon carbide grains fracture easily for fast stock removal.
    • Recommended for cast iron
    • Non-ferrous metals, i.e. brass, aluminum and bronze
    • Non-metallics, i.e. glass, rubber, plastic and stone
    • Final finish on wood and stainless steel
    • Abrasive planing particleboard
  • Zirconia Alumina
    • Zirconia Alumina has a self-sharpening characteristic, giving them long life.
    • The unique quality of being both tough and sharp make it ideal for heavy grinding operations on hard materials.
    • In heavy grinding operations in grits 24-120 the unique feature of controlled fracturing make Zirconia Alumina the best choice.
    • Heavy-duty snagging and grinding of all ferrous and non-ferrous metals
    • Abrasive planing of wood, plywood and particleboard
    • Grinding fiberglass, rubber and plastics.
  • Ceramic
    • Synthetic grain designed to multi-fracture exposing new sharp cutting edges in order to cut cooler even in the most extreme, high-pressure, applications.
    • Performs well in low pressure applications as well where heat is a problem when grinding metal alloys.
    • Very hard and friable abrasive primarily used in metal applications when heavy stock removal is needed.
    • All ferrous/non-ferrous metals, carbon steel and exotic alloys

Grain Hardness Scale

Grain Positioning

There are two ways to grain is applied to a backing; Mechanically coated or Electrostatic coated.

Mechanically coated process allows the grain to fall by force of gravity onto the base coat coated backing.  Mechanically coated abrasives are less aggressive because not all grains are positioned with the sharp side exposed.  

In an electrostatic coating process the grits become charged electrostatically and are attracted to the coating which has a positive charge and will attach to the base coat and coated backing. Electrostatically coated abrasives are more aggressive and provide a higher performance as mechanically coated products.

Grain Distribution

Most coated abrasives fall into either Closed Coat or Open Coat.  A Closed Coated product has 90% to 100% grain coverage. Advantages of a Closed Coated product is there is more cutting edges in action and less scratch depth.  Closed coated products are recommended for very hard materials and when finish is critical. A product which is Open Coated has about 50% to 70% grain coverage. This allows the product to have less clogging since there are free space between grits.  Open coated products also will be more aggressive per square inch as pressure is applied to few grits causing more grain penetration into substrate being sanded. You will want to use an open coated product on soft materials.

Additional Coatings

Many products need an additional coating applied to maximize performance.  A few of the common terms are grinding aid, stearate or anti-static. The additional coatings should be matched up the application to take full benefit of the product.

Coated Abrasive Backings

While the grain of the abrasive is extremely important, choosing the correct backing is critical. The type of backing is determined by the amount of strength and flexibility the abrasive must provide. The basic types of backing are paper, cloth, fiber and film. It is imperative to pair the backing to the application.  Both paper and cloth backings are designated by a letter code; paper A though H, A being the lightest and flexible and H the strongest. Paper backings are graded by weight of the paper in grams per square meter. The stronger the backing the more pressure applied to the grain providing a deeper scratch and more aggressive stock removal.  Fiber backings provide extremely ridged support for grinding discs and film backings allow for excellent edge wear as well as more precise grain height.

Cloth backings are rated based on the flexibility of the backing.  Depending on the manufacture, the coding can vary but the basic range is H to Z; H being very flexible for cloth rolls and Z being very stiff.  Cloth backings can be made of cotton, polyester or a combination of both. Cotton backings are more flexible and cannot be used in wet applications.  Polyester provides more stability and strength. There are also combinations of polyester and cotton backings

Grit Comparison Chart