Quick-change shank. Cuts fast; has improved balance with reduced runout. Shank has flat surfaces for secure chuck grip. Inside cutting plane shaves hole radius. Feed screw provides fast, effortless feeding, even in gummy woods. For 1 1/2 standard pipe sizes. For 1/2 D-handle drills and larger drills.
From the Manufacturer
Has removable and replaceable feed screws. Two feed screws furnished with each bit. Feed screw provides fast, effortless feeding even in gummy woods. Inside cutting plane shaves hole radius for clean, smooth holes without pressure. Bits has a 7/16 hex shank."