Lenox 30883-VB3 Vari-Bit 1/4-Inch to 3/4-Inch Step Drill Bit with 3/8-Inch Shank
The LENOX  30883-VB3 Vari-Bit Step Drill Bit - 1/4" - 3/4"  has a patented two flute design which cuts fast, clean, round holes that are accurate and burr-free.  The enhanced flute design also removes chips rapidly to ensure longer tool life.  The split point on the tip of the Vari-Bit is designed for faster penetration and prevents walking.  The steam oxide coating adds to the durability of the Vari-Bit Step Drill Bit.