I have extensive experience in tapping. In simply refreshing 12-24 threads in the aluminum cook pot of my Weber grill, the bit broke after usual crank/release w/lube operation, what's supposed to be the exact purpose of HSS bits (i.e. tapping aluminum). At the end, I was able do finish the job with some other cheap Chinese tap bit, only because the "Drill America" at least it broke in such a way it was removable. These bits were a total waste of money!!
Rating:
[1 of 5 Stars!]