13G404 - 4-Inch Knot Wire Cup Brush with Safety Ring - Carbon Steel

Aggressive Cleaning for Professional Welders

For welders and metalworkers, surface preparation is a critical step that dictates the quality of the final product. The Walter 13G404 4" Knot Twist Cup Brush with Ring is built to handle the tough reality of the welding shop. Designed to fit standard angle grinders with a 5/8"-11 thread, this brush transforms your grinder into a powerhouse for cleaning and descaling. Its robust construction is optimized for working on steel, making it a go-to tool for prepping base metals or cleaning up finished welds.

Controlled Power with Knot Twist Design

The 13G404 features a knot-twisted wire configuration, which bundles the steel filaments into tight, rope-like strands. This design provides a much higher impact action compared to crimped wire brushes, making it suitable for removing stubborn contaminants like heavy slag, thick rust, and old coatings. The addition of a steel supporting ring around the bristles is a game-changer for performance. It prevents the knots from expanding too wide during rotation, keeping the brush face aggressive and concentrated. As the wire wears down, the ring ensures that the brush retains its shape and effectiveness throughout its lifespan.

Built for the Grind

Walter Surface Technologies is known for producing abrasives that last, and the 13G404 is no exception. The wires are made from premium carbon steel that has been oil-hardened and tempered. This metallurgical processing ensures that the wires stay sharp and resist bending or snapping, which is a common failure point in lesser brushes. The result is a safer work environment with fewer flying wire fragments and a tool that lasts significantly longer, providing better value for your shop.

Perfect Balance and Usability

Vibration is the enemy of precision and comfort. Walter ensures that every 13G404 cup brush is perfectly balanced to run smoothly on your grinder. This smooth action allows for better control when cleaning large flat surfaces or maneuvering around workpieces. The .020" steel wire is aggressive enough to strip surfaces down to bare metal quickly, ensuring excellent conductivity for welding or a clean profile for coating adhesion. Whether you are in a shipyard, a structural steel plant, or a custom fab shop, this brush delivers the reliability you need.