cup brushes

Empire Abrasives Wire Cup Brushes

What is a Wire Cup Brush?

Wire cup brushes are a wire abrasive tool constructed by attaching wire bristles/filaments to a cup-shaped base.  These bristles come in a variety of materials such as brass, carbon steel, and stainless steel. You can also find them in different formats including crimped and (twist) knotted.

What are Wire Cup Brushes Used for?

Cup brushes have a variety of uses on flat, curved, and irregular surfaces including:

  • Metal surface preparation
  • Weld spatter removal
  • Removal of rust, paint, and/or scale
  • Deburring
  • Edge blending
  • Roughening for adhesion
  • Cleaning

You will get different results depending on whether you are using crimped or knotted cup brushes and also depending on the material of the wires.

Knotted Brushes vs Crimped Brushes

As you use your wire brushes, the force against the surface you are grinding on will cause the ends to naturally break off. This is done by design to keep the edge of your brush as sharp as possible by exposing fresh edges instead of dulling over time. Knotted and crimped brushes are designed for different applications based on this function.

Knotted Wire Cup Brushes

Sometimes referred to as a twisted cup brush or twisted knot cup brushes, these are built by twisting the metal filaments together to create stronger, stiffer, cable-like, groupings of the filament strands. By combining the wires in this way, the twisted wire cup brushes can be used for more aggressive applications due to the more rigid structure.

Crimped Wire Cup Brushes 

This configuration appears much different than the knotted brushes. Instead of combining the filament together, they are separated from one another and crimped to keep the wires apart. The brushes are more flexible and have more give than their knotted counterpart. This type of cup brush is recommended for lighter cleaning and polishing.

Wire Cup Brushes for Grinders

Cup brushes are made for a variety of tools, including different grinders. You should always read the product specifications and recommendations, but generally, a wire cup brush for angle grinders will have a threaded arbor hole in the center whereas a cup brush for die grinders and impact drivers will have a hex shank attachment instead.

Wire Cup Brush for Drills

The same cup brushes made for die grinders are also crafted to work with power drills. The wire brushes can connect to most drills if they have the hex shank attachment at the base of the cup.

Wire Cup Brush vs Wire Wheel

The styles of these two abrasive tools are fairly obvious when you compare the two, with the cup brush having a more forward pointing design, and the wire wheel brushes have outwardly fanning bristles and shaped more like a disc.

The shape of a wire wheel allows you to hit surfaces from different angles than cup brushes. They are usually better suited to work in a more targetted area while cup brushes are better suited for quickly working on large surfaces.

Abrasive wire wheel brushes also work with similar power tools depending on the connection such as angle grinders, die grinders, and power drills.  Some of these wheels also work with bench grinders and walk-behind saws.

Types of Wire Filaments

There are many different variations of material that can be used to make up the metal wiring in these cup brushes. Empire Abrasives carries the most commonly needed and most versatile metals: carbon steel, stainless steel, brass-plated steel, and nylon.