Irwin/Hanson UN3 Vise-Grip No. 3 Steel Frac Self Starting Unibit Drill Bit

The Unibit is an incredible tool. I'm a sculptor and interactive museum designer/fabricator, and often need to drill larger holes through stabiles steel pile and sheet. This can easily destroy even the titanium bits, also brand new twist bits as the stainless work hardens. These cobalt Unibits effortlessly plow through the metal one step size at a time in seconds with beautiful results, even with a hand drill. One bit drills hole after hole. I could not recommend more highly.