needed a reduced shank for my 1/2" drill chuck. drilled a "perfect" hole in aluminum, had to put a 14mm "boss" on, so had to file a bit to get a few microns gap
If I could put a 0, I would. Drilled a hole in a 3/16" board after clambering through various sizes of other bits and oil cooling. After the first hole, the chisel tip splintered and became sooty. The second hole couldn't be drilled to the end, I had to drill it out with a grinder. Good thing I only needed two holes.
Pros
Cutting edge diameter: 14 mm / 0.55 inch (9/16 inch); Shank diameter: 12.7 mm / 1/2 in.
The drill did the job I wanted for less than half the price an Australian hardware store would sell. Per. The drill was sold as an HSS drill, although not marked as such, but worked as an HSS drill. Although I'm retired, I'm a qualified locksmith and mechanic, so I can say I'm satisfied with the drill.