Morse, MHS56 (177566), 3-1/2" (89mm) diameter, bimetal hole saw is designed for general purpose use, cutting a wide range of materials including stainless steel, machinable metals, wood and plastic. Aggressive, positive rake tooth profile penetrates material easier and faster. Unique side slot increases leaverage access for various thicknesses of materials, easing slug removal. One (1) hole saw per box. Seperate arbor required, use MA35PS (139021) or MA45PS (139038)