Boris Beizer wrote:
I like the Yankee so much that I've adapted other shanked bits
to its use.

I have one in my camping gear. There's an easy modification
that really increases their adaptability: Take a magnetic
bit holder for an electric screwdriver, grind the shank round,
then grind in the step and retaining notch. Or it you wanted,
you could probably weld up something using a worn out Yankee
bit. This gives you access to all the modern interchangable
hex bits...

I still see them regularly at my favorite used tool store, and
the proprietor usually has a tray full of the bits on hand as
well.

You can help reduce the slipping problem by holding the collar
of the bit chuck (which rotates) tight against the screw while
you work the handle with your other hand.

--Glenn Lyford