OSG, 1/4 in Drill Bit Size, 2 1/2 in Overall Lg, Screw Machine Drill Bit - 2PPN5|220-2500 - Grainger
General Tools Drill Bit Sharpener & Grinding Tool Attachment 825 - The Home Depot
CoCud Tap and Drill Bit Set, 3/8-18 UNF 2B Tap Thread 8.1mm Drill Diameter, Machine Screw Tap & Twist Drill Bit Tool Kit - (Applications: for Threading Tapping Repairing), 1-Set - Amazon.com
7pc Square Hole Mortise Chisel Drill Bit HSS Woodworking ...