VARIABLE PITCH TYPE; STEAM OXIDE FINISH; FERROUS METAL, NON-FERROUS METAL, NON-METALLIC CUT MATERIAL; BI-METAL BLADE MATERIAL; 7/8 INCH DIAMETER; 390 RPM (MILD STEEL), 260 RPM (CAST IRON), 520 RPM (BRASS), 585 RPM (ALUMINUM) SPEED RATING