13G304 - Walter 3-Inch Knot Twist Wire Cup Brush with Ring - Steel .020

Aggressive Rust and Slag Removal

When you need to strip a surface down to bare metal fast, the Walter 13G304 3" Knot Twist Cup Brush is the tool for the job. Built for professional welders and fabricators, this brush combines the aggressive cutting power of knot-twisted wire with the longevity provided by a support ring. The .020" steel wire is stiff and durable, capable of digging into pits and crevices to rip out rust, scale, and weld slag that softer brushes leave behind. It is the perfect companion for your 4.5" or 5" angle grinder, threading directly onto the 5/8"-11 spindle.

The "W/Ring" in the name refers to the metal band that encircles the wire knots. This isn't just for packaging; it's a performance feature. By holding the knots tight, the ring prevents them from splaying out under high RPMs. This keeps the wire tips stiff and perpendicular to the work surface, which is where the cutting action happens. The result is a brush that cuts faster and lasts significantly longer than standard knot cups. It is particularly effective for cleaning weld passes, preparing bevels for welding, or stripping paint from structural steel.

Walter Surface Technologies is known for manufacturing brushes that are perfectly balanced. An unbalanced brush on a grinder spinning at 10,000+ RPM creates vibration that numbs your hands and fights your control. The 13G304 spins true, allowing you to work with precision and comfort. If you are working with carbon steel and need a brush that can handle the heat and abuse of daily fabrication work, this is the cup brush to keep in your toolbox.

Applications for Welders

Use this brush for post-weld cleaning to remove stubborn slag, especially from flux-cored arc welding. It is also excellent for pre-weld prep, ensuring your base metal is free of contaminants like heavy rust or mill scale. The 3-inch size is versatile enough for flat surfaces while still being compact enough to maneuver around some irregularities.