Pack includes: 3 inch knotted wire wheel*4, 4 inch knotted wire wheel*4 Material and Construction - Both wire wheel brush and cup brush are made of high quality carbon steel. - Wire thickness: 0.020 in hardened carbon steel wire; 100% inspected for quality. - Max RPM: 12,500. Suitable for angle grinders with 5/8 in 11 NC threaded shank. - Uses: removes severe corrosion, rust, paint, spatter and scale; also cleans weld edges to remove burrs. High Quality - 0.020 in high-strength hardened carbon steel wire delivers four times better performance than many rivals and maintains strong knotting integrity. Design - Knotted cup brush features a thick knotted cup design for heavy, aggressive surface treatment over large areas. - The thinner, curly cup design offers maximum flexibility and fatigue resistance, while minimizing the risk of scratches on expanded metal surfaces. Applications and use scenarios - Remove heavy rust and old coatings from structural steel, machinery, and equipment. - Clean welds and deburr edges during fabrication or maintenance. - Prepare expanded metal and large flat surfaces for coating with reduced risk of scratching. Compatibility and performance - Works with angle grinders that use a 5/8 in 11 NC threaded shank. - Designed for high-speed surface preparation on metal with controlled aggression and durability.