This 6-piece set of Irwin Blue Groove SpeedBor Auger wood drill bits (Model: iw4042202) is designed for fast and clean drilling in all types of wood with minimal effort. These bits feature a Tri-Flute design for faster chip ejection, full screw tips for self-feeding and ease of use, and cutting spurs with three cutting edges for clean holes and durability. The tapered flute reduces binding, and the full length heat treatment provides extra durability. The 1/4" grooved hex shank prevents slipping in drill chucks or extensions and fits all standard 1/4" quick change chucks. The set includes bits in sizes 16mm, 18mm, 20mm, 22mm, 25mm, and 32mm, all stored in a heavy-duty Irwin case.