Kevlar thread. Later smeared with epoxy. Sole was drilled ~1/16" holes.
Tiny cherry cup turned from flawed knob blank.
My favorite threaded knob design. Heavy 1/2-13 nuts, mortised in. I turned them of cherry and oiled them with 'butcher block oil' to retain full grippiness. These will be for locking the arms on some wooden tripods I made, photos of them coming soon.