Parabolic drill bits can be used for any number of projects. They come in a range of sizes, from one-sixteenth inch to over an inch in diameter. They can drill starter holes for screws, partial holes for dowels and clear holes for bolts. However, parabolic drill bits are most often used for deep hole drilling. Due to their unique design, parabolic drill bits drill holes faster than other drill models. The parabolic spiral allows chips to flow up quickly, not blocking the hole or requiring frequent drill bit withdrawal to clean out wood chips. Parabolic drill bits rarely shred the area surrounding entry and exit holes, leaving less damage to be corrected after drilling. Parabolic drill bits last a long time, with breakage a problem only with the smallest bits (under three-sixteenth inch in diameter).