Forstner Bit, measures 3-1/2 inches in overall length, with a 1-3/8-inch diameter cutter, bores precision holes at any angle, features a brad point to start the bit cleanly, even on uneven surfaces and extra sharp cutting edges to drill smooth, flat-bottomed holes. Bit has a reduced shank to fit 3/8-inch drills and drill presses. Irwin tools are made of only the finest materials, manufactured to exacting tolerances.