Harbor Freight sells one of those "tools you put in your toolbox
and only get out rarely when all else has failed." It's called an
impact screwdriver. They've been around forever, and the one I
just got cost less than what I paid for one 55 years ago.

What they are is a very heavy solid steel handle with a coarse
pitched screw thread inside, so to speak. Inside the threaded
area is a mated shaft with reversing toggle, and on the end of the
shaft is a hex holder for various screwdriver bits. The tool is a
heavy duty version of the Yankee drill we all remember. They have
a socket wrench-type of shaft and apparently can also be used on
bolts, but I've never tried that, since I have a pneumatic wrench
that works well. Their best application is in loosening frozen
screws, where an inward application of force and twisting motion
is needed.

To use the impact screwdriver, you place the appropriate bit in
the holder and hold the screwdriver firmly while tapping on it
with a hammer. The impact forces the bit into the screw, helping
to prevent the head from stripping, while the coarse threads make
the bit twist just a tad. Usually, that's enough to break loose a
frozen screw if you're lucky, and you then follow up with a
regular screwdriver to finish the job.

The first one I had I bought as a teen to work on my motorcycle's
engine and had it for around 40 years. During that 40 years, I
probably had to use it a dozen times at the most. However, each
and every time it saved the day for me. The one Harbor Freight
sells appears to be a clone of my old one and I suspect it'll
serve the purpose longer than I'll ever need.

Nonny

--
On most days,
it's just not worth
the effort of chewing
through the restraints..