VARIABLE PITCH TYPE; STEAM OXIDE FINISH; FERROUS METAL, NON-FERROUS METAL, NON-METALLIC CUT MATERIAL; BI-METAL BLADE MATERIAL; 13/16 INCH DIAMETER; 425 RPM (MILD STEEL), 280 RPM (CAST IRON), 560 RPM (BRASS), 635 RPM (ALUMINUM) SPEED RATING