Speedbor Max is the fastest Speedbor Ever . Tri-flute design for faster chip ejection. There are 3 cutting edges for added durability and the full screw tip allows the bit to self feed for easier pull-through. 1/4" quick change hex shank prevents slipping in drill chucks and bit extensions. Fits all standard quick change chucks and adapters. Set includes 5/8", 3/4", and 1" Speedbor Max.