This countersink works very well, but using it for a couple of hundred holes in 1/4 aluminum plate revealed a slight issue. The aluminum likes to stick to the countersink. Not really a fault of the tool, as aluminum likes to stick to high speed steel tooling in general. Great value for the money, but a cobalt or carbide tool may be a better option if you need it for a lot of aluminum.Still, if you don't want to spend 5x the money for a bit, this is a great value.
Rating:
[4 of 5 Stars!]