This Irwin Blue Groove Drill Bit Set contains a selection of Blue Groove 4X Flat Drill Bits and Blue Groove 6X Auger Drill Bits. All bits are heat-treated for maximum durability. The Blue Groove design allows them to cut smoothly without scraping the timber. They have an optimised design for maximum chip ejection and a quick-release hex shank. Supplied in a handy, heavy-duty container with the following bits: 5 x Blue Groove 4X Flat Drill Bits (152mm Long): 12, 16, 18, 20, 22mm 3 x Blue Groove 6X Auger Drill Bits (165mm Long): 22, 25, 32mm