VARIABLE PITCH TYPE; STEAM OXIDE FINISH; FERROUS METAL, NON-FERROUS METAL, NON-METALLIC CUT MATERIAL; BI-METAL BLADE MATERIAL; 5/8 INCH DIAMETER; 550 RPM (MILD STEEL), 365 RPM (CAST IRON), 730 RPM (BRASS), 825 RPM (ALUMINUM) SPEED RATING