Review on Enhanced Performance with Drill America Cobalt Economy Degrees: Unleash Your Drilling Capabilities by Ryan Koser

If I had read the description more carefully I would not have bought them. I thought I would buy a drill but the price was for twelve. It would be a red flag. These bits were very cheap for the price. I bought a bit to drill through 2mm thick stainless steel. I have other bits that bite and cut well. These bits hardly leave any marks on the surface. I do not recommend these bits for metal drilling. Maybe aluminum.