Bahco 228-sd, 229-sd and 230-sd set

Includes 3 pieces|4 mm to 12 mm in 1 mm increments|4 mm to 22 mm in 2 mm increments|5 mm to 35 mm in 13 mm increments|Step drill set for making holes in thin sheet metals|Titanium-nitride (TIN) coated step drill with a surface hardness that makes the tool last 4 to 5 times longer than ordinary step drill bits|Same surface reduces friction, resulting in a tool that runs cooler and effective, self-lubricates while running dry|Self-centering point|Shank size 1/4" (6.35 mm) and 3/8" (10 mm) and 1/2" (12.7mm)|For making holes in thin metal sheets|Last up to five times longer than ordinary step drills|Titanium-nitride (TIN) coating with a surface hardness|Self-lubricates while running dry