Specifically designed for hand held operations in materials up to 3/8 in. thick, these Carbide tipped steel plate cutters stay sharper longer than high speed steel or bi-metal hole saws. They produce drill press quality holes even in hand held operations. For cutting materials over 3/8 in. up to a depth of 1/2 in., a drill press is recommended. When cutting depth is over 1/4 in., use Hawg Wash cutting fluid to keep cutting surface cool and lubricated. Hawg Wash fluid is available in 16 oz. Bottles (49-32-0081). One bottle makes one gallon of lubricating solution. 13/16 in. diameter.