VARIABLE PITCH TYPE; STEAM OXIDE FINISH; FERROUS METAL, NON-FERROUS METAL, NON-METALLIC CUT MATERIAL; BI-METAL BLADE MATERIAL; 1-1/2 INCH DIAMETER; 230 RPM (MILD STEEL), 150 RPM (CAST IRON), 300 RPM (BRASS), 345 RPM (ALUMINUM) SPEED RATING