Lenox 30908-VB8 Vari-Bit 3/16-Inch to 7/8-Inch Step Drill Bit with 3/8-Inch Shank
The LENOX  30908-VB8 Vari-Bit Step Drill Bit - 3/16" - 7/8"  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.