What is a Flap Disc?

  • Flap discs are constructed by layering coated abrasive flaps so they wear away and expose new, sharp grain
  • Flap discs increase productivity and reduce total grinding and finishing costs by grinding, blending & finishing in 1 step

Backing Shape

Conical shape features (type 29):

  • Built-in angle for increased contact area
  • Best for use on contoured surfaces and edge work
  • Minimizes workpiece gouging
  • More aggressive stock removal due to higher angle
  • 15°-25° working angle

Flat shape features (type 27):

  • Best for use on miter joints, corners and edges
  • Best choice for finishing intricate and ornate surfaces
  • Ideal for smooth finishing
  • 0°-15° working angle

Backing Type

Fiberglass backing features:

  • Backing will wear uniformly with abrasive cloth
  • Will not splinter or smear on the workpiece
  • Lighter, quieter operation

Plastic backing features:

  • Non-scratching, high strength backing
  • Resistant to temperature extremes, common chemicals and solvents
  • Some plastic backings are trimmable


High density flap discs contain approximately 40% more material than regular density flap discs.

Flap Discs vs. Grinding Wheels

  • Faster stock removal and smoother finish
  • Quieter operation and reduced vibration minimizing operator fatigue
  • Cooler cutting, reduced loading and glazing
  • Easy to use – reduced gouging and rework

Flap Discs vs. Fiber Discs

  • Up to 20 times longer life than a fiber disc
  • No backing pad needed
  • Easier storage – no curling
  • Flap discs should use one grit coarser than used in fiber discs (except 36 grit)
  • More consistent finish

The United Abrasives Difference

Two Types of Plastic Backings

  • Soft ABS Plastic designed to be trimmed to expose more abrasives material
  • Hard Plastic designed for high strength and rigidity promoting ease of use and long-life

Fiberglass Backing

  • Custom engineered fiberglass backing plates for strength and safety
  • More fiberglass than competitors – making our flap discs among the safest on the market

Adhesive System

Specially formulated adhesive system, designed to effectively secure the abrasive flaps to the backing, maximizes abrasive performance and safety

Coated Material

  • Our own coated material has been specifically designed for flap discs
  • Unique materials are used for each flap disc application

Flap Design

  • We utilize more and larger flaps than our competitors to yield great performance and product life