PFERD Stem mounted standard twist knot wire wheel brush is more aggressive brushing action than crimped wire for faster removal. For deburring, cleaning, rust removal and weld seam conditioning. Recommendation for use Suitable tool drives: straight grinders, flexible shafts, power drills. Specification: Grit Material: Carbon Steel Wire; Diameter (Inches): 4; Stem Diameter (Inches): 1/4; No. of knots: 22; Trim length (Inches): 3/4; Face width (Inches): 5/8; Wire diameter: .014; Recon. Speed (RPM): 12,500 - 18,700; MSFS max. (RPM): 25,000.