The backing can vary in flexibility and come in different types such as paper, cloth, cloth-paper combinations, film, or vulcanized fiber.

Cloth backings can range from extremely flexible (e.g., type E cotton backings) to extremely durable (e.g., type Z polyester backings).

Paper backings are available in various weights, from the lightest (type A) to the heaviest and most robust (type H). These backings serve as the foundation for various abrasive formats, including rolls, belts, discs, specialty products (cones, spiral bands, multi-rolls, reinforced belts, quick-change discs), and flap products (flap discs, shaft-mounted flap wheels, flap wheels with hole and thread).

A flexible abrasive typically consists of four to five components:

  • Backing material

  • Base bond

  • Abrasive grain

  • Top bond

  • Additional coating (cooling or anti-loading layer)


    Abrasive Backings

    The abrasive grain is affixed to a backing that retains the grain and transfers cutting forces to the workpiece. The available backing materials include:

    Cloth Backing

    • Materials: Aramid, cotton, polyester, and polycotton

    • High tear resistance

    • Varying flexibility, from highly flexible to very rigid

      Backing Flexibility Typical Applications
      E Extremely flexible Profiled workpieces
      F Very flexible Profiled workpieces
      J Flexible Profiled workpieces
      T Semi-rigid Mini belts / file belts
      X Rigid Flat surfaces, edges
      Y Very rigid Flat surfaces, edges
      Z Extremely rigid Edges and heavy-duty sanding
    Vulcanized Fiber

    • Multi-layer composite paper material

    • Extremely tough and highly tear-resistant

    • Primarily used for fiber disc production

    Paper Backing

    • Excellent stretch resistance

    • Smooth operation with appropriate bonding types

    • Lighter than cloth backings

    • Various grades available to provide the required flexibility and strength for each process

    Cloth-Paper Combination Backing



    Backing Paper Density Typical Applications
    A ~70 g/m² Manual profiling and surface polishing
    B ~100 g/m² Manual profiling and surface polishing
    C ~120 g/m² Manual surface sanding
    D ~160 g/m² Manual/machine surface sanding
    E ~250 g/m² Large surface sanding
    F ~300 g/m² Large surface sanding
    G/H ~350/400 g/m² Heavy-duty sanding on large surfaces





    Combines the strength of cloth with the lightness and machine adaptability of paper. Especially recommended for segmented belt manufacturing.

    Film Backing

    Highly tear-resistant material. Excellent grain adhesion and highly suited for curved workpieces. Its hardness and uniformity make it ideal for fine finishing with consistent surface roughness throughout its lifespan.

    Abrasive Components

    Base Coat

    Holds the abrasive grain in place. Typically made of phenolic or urea resins, with fillers added to enhance properties like flexibility or water resistance.

    Abrasive Grain

    This is the component that performs the cutting, penetrating the surface and removing material. The most important properties are hardness, toughness, and sharp edges.

    High-performance abrasives are made from the following synthetic materials:

    • Silicon Carbide: Extremely hard, ideal for titanium, glass, minerals, ceramics, porcelain, and stone.

    • Aluminum Oxide (Corundum): Versatile grain used across many industrial applications. Excellent balance of toughness and hardness, ideal for intermediate sanding and finishing.

    • Zirconia: Self-sharpening abrasive with high material removal rate for medium to high pressure applications.

    • Ceramic: Geometrically shaped grains for maximum cutting speed and lower surface temperature. Significantly longer lifespan.

    • Cubic Boron Nitride (CBN): Exceptionally hard, long-lasting, suitable for both dry and wet use. Recommended for materials like high-speed tool steels, die steels, alloy steels, hardened carbon steels, aerospace alloys, stainless steels, and abrasion-resistant ferrous metals.

    • Diamond: Ultra-hard with long service life. Ideal for machining hard, brittle materials like tungsten carbide, glass, ceramics, fiberglass, plastics, stone, and electrical components.

    Grain Coating

    The orientation of abrasive grains determines the final surface quality. Electrostatic coating is the primary method used to position grains vertically on the backing for optimal sharpness.

    During this process, grains are accelerated through an electrostatic field to align vertically on the substrate, enhancing cutting performance.

    There are three coating types:

    • Closed (Standard): Grains are densely or semi-densely spaced.

    • Combination: Supporting grains are added between abrasive grains to ensure vertical alignment, especially useful when machinery limits contact pressure.

    • Extra Open: Greater spacing between grains enhances self-sharpening effects and chip evacuation while reducing material adhesion.

    Intermediate Coat

    Ensures proper anchoring of the abrasive grain. While the base coat bonds to the backing, the intermediate coat bonds to the base and firmly secures the grain in place.

    Abramaster Abrasive Belts and Discs — Additional Active Layers

    Some abrasives feature up to three different top coatings:

    • Cooling Agents: Recommended for dry grinding of stainless steels and heat-sensitive non-ferrous metals. These additives improve cut performance and lower contact area temperature, significantly extending product life.

    • Stearate Coating: Enhances cut efficiency on soft materials (like aluminum) by reducing material buildup on the abrasive grain.

    • Antistatic Coating: Used mainly for woodworking, preventing electrostatic charges that cause sanding dust to stick to workpieces or machinery.