Flap Discs Application Guide

What is a Flap Disc?

Flap Discs are a cost-effective tool designed to grind and finish in one operation. Therefore no additional tools are backing pads are necessary, saving you time and money.

Safe, quiet, easy to control, and with a long life, flap discs are made with glued layers of abrasive material that wear evenly, and continuously expose new sharp grain for aggressive stock removal and a consistent, smooth finish.

Diagram of Flap Layering
Layered abrasive flaps allow for aggressive stock removal and a smooth, consistent finish

How are Flap Discs Made?

Imported from a leading manufacturer in Germany, abrasive cloth is cut to size and arranged in layers to create flaps of abrasive material. Eight layers of fiberglass or specially designed plastic and aluminum backings provide a safe support for abrasive flaps, eliminating backing pads required for conventional paper, cloth or fiber discs. Fiberglass backing does not contaminate or damage the surface of the work piece. Industrial adhesives provide a structural bond between the abrasive material and the backing for safe grinding.

Grit Identification Table


Depending on the grinding angle and surface to be ground, flap discs are available in two styles:

Type 27 Flap Disc Diagram
For grinding at a 0 - 15° angle. Suitable for flat surfaces.
Type 29 Flap Disc Diagram
For grinding at a 10-25° angle. Suitable for contoured surfaces.

Features & Benefits

Features & Benefits

Advantage Vs. Other Products

A single flap disc can be used to not only to grind a surface, but finish as well. In the past these operations would require a grinding wheel as well as a fibre disc. Thus, flap discs eliminate the need to swap tools and equipment, thereby improving productivity.

Vs. Grinding Wheels

Vs. Fibre Discs

Flap Disc with Safe Loc

More aggressive
Cooler cutting
Better surface finish
Less vibration
Less noise

Energy Grinding Wheel
Flap Disc with Safe Loc

20 times longer life
Fewer disc changes
Consistent finish
No back-up pad
Easier storage

Fiber Disc

Working Pressure: Higher pressure for stock removal, lower pressure for finishing.

Finish: Use one grit size coarser than fiber discs, except for 24 and 36 grit.

Extreme Abrasives’ patented SAFE LOC technology is available on all 4½”, 5″, and 6″ flap discs