Necklace Clasp System

Dan, what you have designed is an metal version of a very common
knot that bead stringers have used for centuries with goat thong or
leather. Instead of your cylinders, envision knots tied around the
other cord. The whole thing operates just like yours does, except
each side of the thong slides through the knot on the other side that
is tightened “just enough”. Yours is much more elegant!

Rene Roberts