Ask any woodworker if he can drill a square hole, and he'd say that of
course ... with a hollow
square mortise chisel & bit. But that's kind of cheating: it's
basically drilling a round hole and chiseling the rest to make the square
But did you know that there is a way to actually drill a square hole?
With a Harry Watts square drill bit (named after its inventor, who patented
it back in 1917). Here it is in
Confused? Here's a neat
animation that shows what exactly is happening (hint: the bit is shaped
like a Reuleaux
Pretty nifty, huh?