Cup brushes are abrasive tools comprised of wire bristles or filaments attached to a cup-shaped base. Brass, carbon steel, and stainless steel are some of the materials used to make these brushes. They’re also available in a variety of styles, including crimped and (twist) knotted. Wire cup brushes can be used on flat and curved surfaces, including surface preparation, rust, paint and scale removal, deburring, cleaning, edge blending, and more.

Although you should always check the product specs and recommendations, a wire cup brush for angle grinders will typically have a threaded arbour hole in the centre.

Crimped wire cup brush vs knotted wire cup brush

Before installing and using wire cup brushes, ensure you have the proper equipment for the job. Unlike knotted types, where filaments are joined, crimped brushes’ wiresare separated and crimped to keep them from tangling. Compared to their knotted counterparts, the brushes are more flexible and have more give. This style of cup brush is excellent for cleaning and polishing small areas.

Knotted cup brushes are created by twisting metal filaments together to form stronger, stiffer, cable-like groupings of strands. Because of the more solid structure created by joining the wires in this manner, the twisted wire cup brushes can be utilized for more aggressive applications.

Remember:

• The angle grinder of drill should not be held stationary – continue to move the brush across the material’s surface.
• Don’t apply excessive pressure.
• Do not use a carbon steel brush on a stainless steel surface.
• Do not use an angle grinder with a missing or damaged guard.