Taper Cone Drill
Conical, two flute construction drills burn-free holes from 1/8" to 1-1/8" diameter in metal, plastic, or wood. A washer can be placed on cone to act as a simple stop-gauge. Ideal for sheet metal and hole enlarging work.
Tapered Cone Drill - High Speed Steel page 118

Tapered Cone Drill - TiN Coated page 118