These Dremel accessories (531) are stainless steel brushes designed for cleaning corrosive resistant metals Rust-free: Stainless steel brushes do not cause “after rust” when used on corrosive-resistant materials like pewter, aluminum and stainless steel Ideal to use on a variety of surfaces including steel, aluminium, brass, silver, gold and other metals Working diameter 13.0 mm; shank diameter 3.2 mm; recommended maximum speed 15,000 RPM Fits with all Dremel Multi-/Rotary tools or other 3,2mm shank size multi- / rotary tools, Weight: 0.0220462262 pounds, Manufacturer: Dremel