Review on HQMaster Engraving Tungsten Titanium Aluminum by Larry Sabey

I have used these bits with wood and they seem to work fine. I want to push them hard at a feed rate of 10 inches per minute. As soon as I switched to a real aluminum part, the bits started breaking. I even slowed the feed down to 1 IPM but the tips were still breaking off. Upon closer inspection, the taper notches on the bits are very poorly cut. Surprising because I've had great luck with HQMaster flat head milling cutters.