Durable materials and processes: The knotted wire wheel and cup brushes twist the steel wires together for increased resistance to pressure and durability.Hardened steel wire for reduced wire breakage & long life. These twisted wire brushes are suitable for removal of rust, corrosion,paint,deburring and surface conditioning.Ideally suited for cleaning castings, structural steel and sheet metal. 1/4"shank fits most drills. Maximum 4500 RPM.Package Included: 1pc × Knotted wire wheel brush,1pc × Knotted Steel Wire Cup Brush,1pc Knotted end brush