*Dimensions not as stated. My kit included a 3/16" radius drill instead of a 1/2" radius drill. I was expecting something like this based on other reviews.* One bit had blackened cut edges (see photo). This leads me to suspect a problem with the heat treating or grinding processes, but I guess that's perfectly normal. I'm not an expert and I don't know how to diagnose this.* In one case the carbide was not properly brazed to the steel beam (see photo). This defect significantly increases the stress on the relatively brittle cemented carbide. Other issues didn't bother me much, but this one seems dangerous.