That’s a Knotted Wire Wheel Brush / Twisted Knot Brush for Angle Grinder
Details from the hub:
• Brand: OTTO - GERMANY
• Max Speed: 12,500 RPM
• Type: Twisted Knot Wire Wheel
What it’s used for:
This is the "heavy duty" version of a wire brush. Because the wires are twisted together in knots, it's way more aggressive.
1. Heavy Rust Removal - Strips thick rust, scale, and corrosion from steel
2. Paint & Coating Removal - Removes old paint, epoxy, undercoating fast
3. Weld Prep & Cleaning - Cleans weld seams, removes slag on carbon steel
4. Surface Prep - Preps steel before welding, painting, or galvanizing
5. Concrete/Masonry Cleaning - Also used to clean concrete surfaces