No. 821 Carbide-Tipped Blade Carbide-tipped replacement blade for the Crain No. 812 Super Saw, No. 820 Heavy-Duty Undercut Saw, or No. 825 Heavy Duty Undercut Saw. The large 6 ½" diameter allows these Crain saws to fully undercut inside corner areas. The 40 carbide teeth and precision-formed steel blade body produces smooth and accurate cuts. For use in undercutting wood doors, wood jambs, wood base or drywall only. Not for use on any metal, masonry, stone, or ceramic tile materials. (See the No. 805 Masonry Blade or No. 822 Diamond Blade for undercut saw blades that cut masonry or stone.) Net weight: 6 oz.