Type 229-SD
For making holes in thin 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 whilst running dry.
Drills holes from 4 to 22 mm Shank 3/8” (10 mm).