Alex...
It isn't so much about strength as it is about ability to
withstand heat. The cutting spurs are fairly vulnerable when the
bit is turned very much faster than a human can manage with a brace.


Aah yes..."heat"...of course. Makes much more sense. Thank you!

(I am still "fetus-of-neanderthal"... not set set up to start learning yet,
whilst I collect the tools.)

Alex