The Hitachi 728499 Heavy-Duty 6-Inch Auger Drill Bit Set with DuraCore comes with 4-pieces measuring 3/8, 1/2, 3/4 and 15/16 of an inch by 6-inch long. Hitachi DuraCore treated premium Auger bits are designed to remain sharp for the entire job. The self-feed tip pulls the precision spur into the wood, which cuts a clean hole, while the wide throat flute design evacuates the chips efficiently.