IRWIN Unibit 3-Piece Set Step Drill Bit Set (3/16-in to 7/8-in) in the Step Drill Bits department at Lowes.com
Step Bit, Small 1/8" - 7/8" in 1/16" increments
Step Drills - Malco Products
Titanium Step Drill Bits | 3pc SAE Unibit Set 28 Reamer Bits 1/8" to 3 - California Tools And Equipment
Amazon.com: CO-Z Large HSS Spiral Groove Step Drill Bit, 12 Sizes Titanium High Speed Steel 1/4" to 2-3/8" Drill Bit for Sheet Aluminium Metal Wood Hole Drilling, Big Multiple Hole Stepped Up
Kennametal - Subland Drill Bit: 8.5 mm Drill, 12 mm Step, 102 mm OAL - 58476151 - MSC Industrial Supply