Bahco Step Drill - 13 steps
For making holes in thinner metal sheets|Titanium-nitride coated step drill with a surface hardness that makes the tool last 4 to 5 times longer than ordinary step drill bits. That same surface reduces friction, resulting in a tool that runs cooler and, in effect, self-lubricates while running dry|Drills holes in 13 steps from 5 to 35 mm|Shank 1/2" (12.7 mm)