Application: drill pocket-holes, flat-bottom holes, etc., using any 3/8" Or larger portable drill or stationary drill press. Forstner pattern bits are well known for their ability to drill clean and chip-free holes in wood. Amana Tool uses only the finest quality tool steel, precision machined and ground on state-of-the-art equipment. Large gullets milled in the tool body provide exceptional chip clearance., #FO-413, (D) diameter: 1-5/8, (D) shank: 3/8, overall length (L): 3-1/2, FO-413 forstner pattern bit 1-5/8 dia x 3/8 shank