|Home made tungsten carbide lathe bit.
I made this tungsten carbide-tipped lathe bit myself, practically from scratch. Seriously, I used an acetylene torch and a graphite mold to sinter together tungsten carbide and cobalt powder (cobalt is the binder that holds together the very hard particles of tungsten carbide). Then I ground and sharpened the resulting pellet on a diamond wheel and silver soldered it to a steel shank (I was fortunate to run into an employee at my favorite welding company who knew exactly the right type of brazing material and flux to use). It actually works, though in practice it is of course much easier, and cheaper, to buy commercially produced bits (see the neighboring sample for and example of such a commercial bit).
You can read more about this bit and see it in action in my Popular Science column on the topic.
Source: Theodore Gray
Contributor: Theodore Gray
Acquired: 1 December, 2008
Text Updated: 2 December, 2008