You get high performance stagger tooth design on all larger diameter bits (over 1 or 25mm) for clean sharp holes with straight sides and flat bottoms. CMT 537.381.31 Forstner Bit 1-1/2 inch. Used to drill precise flat bottom holes with no chipping in any softwood thickness. Specifications: D: 1-1/2; L: 3-35... CMT Forstner Bit, 1-1/2-Inch Diameter, 3/8-Inch Shank 2 spurs, 2 precision ground cutting edges, long-lasting cutting performance. From the Manufacturer CMT offers a wide range of HHS Forstner Bits in the most popular diameters, including difficult to find metric sizes. For drilling partially overlapped flat bottom holes or niches used to fix supports. CMT Forstner bits are 3-9/16 in overall length. Flat Bottom Wood Drill Bit CMT 537.280.31 Forstner Bit, 28mm (1-7/64-Inch) - Dewalt Cmt 537.381.31 1 1/2-inch Forstner Bit X These bits are available individually or in beautiful wooden box sets. CMT Forstner Bit | Forstner Bits Amazon. For drilling niches used to fix supports.