1-1/2" diameter Carbide Grit Hole Saw. 38.1mm These High Quality Carbide Grit Hole Saws are designed for use in hard or abrasive materials such as cast iron, ceramics, fiberglass, hard woods, and composites. They are best suited for thin materials that would strip bi-metal or carbide teeth. Saws have knock-out holes for easy core removal. Use a carbide tipped pilot drill bit when drilling ceramics. These high quality Hole Saws are proudly Made In The U.S.A.