For materials up to 3/16 in., these Carbide tipped sheet metal hole saws produce fine holes in stainless steel or structural steel studs. They can also improve your production in brass, aluminum and other thin sheet materials. Can be used in hand held drills to achieve drill press quality holes. Lubrication during drilling extends the life of the Carbide. Milwaukee recommends the use of Hawg Wash cutting fluid for best results. Hawg Wash fluid is available in 16 oz. Bottles (49-32-0081). One bottle makes one gallon of lubricating solution. 2-1/4 in. diameter.