Broco Diamond Rescue Saw Blades cut metal, concrete, correctional glass and ceramics. Intended for use with gasoline and battery-powered saws with 1″ or 20mm diameter arbors, standard Diamond  The 9″ rescue blade fits a 7/8″ arbor. The 12″ and 14″ blades are solid core for maximum durability. The diamond electroplate facing protects the core, reduces heat, and prevents binding