Double Helix, SEXtuple Helix

[Jim Coleman, Sr.]

Hi to all:

Some on this list have wondered about double helix threads on agraffes.
I liked the exercise of wrapping a thread around the shaft to see where 
it ends up after just one revolution.

Now for a sex thriller, try this same trick on a tuning pin. You will
find that there are six threads per revolution around a tuning pin.
Sometimes they overlap and make the tuning pin a little rough. This can
account for some of the variation we experience in final torque 
measurements.

Getting back to double helix. You may remember that the Kimball co. used
many double helix screws in their case work. This cut the time in half 
that it took to run a screw down. They were also harder to remove.

Jim Coleman, Sr.