Review on Hymnorq Cobalt Metric Enlarge Stainless by Michael Tegan

I bought these to make round holes in sheet metal for rivets. It was a bad choice. The drills are much smaller than they should be. For example, a 9mm hole is 8.70mm, 8mm is 7.65. Thus, a 9mm or 8mm diameter rivet will not fit through the hole. And using the next size up is totally unacceptable. I have to use standard bits to widen the hole so I can insert the rivet. Note: The size of the rivets is usually smaller by about 0.1mm to make room. I would return them except my return window expired before I found out what the problem was.