The Speedbor Max spade bit set from Irwin has a tri-flute blue groove point design allowing for faster chip ejection, making this wood boring bit the fastest Speed bore bit ever! Speedbor Max"s double edged cutting spurs have 3 cutting edges for added durability. The grooved hex shank prevents slipping in drill chuck or bit extension and the full screw tip allows the bit to self feed. This is a 6-piece set which includes bits in sizes of (1/2, 5/8, 3/4, 7/8, 1 and 1 - 1/4-Inch). For fast, rough or clean and exact holes, this wood boring drill bit set provides the user with the best available tool for every wood drilling need.