Hole saws made of bi-metal with hardened cobalt teeth. Quicker chip removal through a new kind of teeth with irregular tooth shape and division; giving much quicker cuts with less vibration. The larger teeth gaps and the inclination ensure effective chip removal. Quicker and softer chip removal through new kind of teeth with irregular tooth shape and division; thus less vibration For use in cast steel and grey cast iron, stainless steel, constructional steel, aluminium, bronze, copper, PVC, acrylic glass, wood. Maximum cutting depth approximately 40 mm Thread for hole saws-O 14-30 mm: 1/2"-20 UNF; thread for hole saws-O 32-152mm: 5/8"-18 UNF Use hole saws only with the corresponding arbor and pilot drill. For hole saws with O 14-30 mm use arbor with 1/2"-20 UNF. For hole saws with 6 32-152 mm arbor with 5/8"-18 UNF. Diameter: 24 mm / 15/16 " mm