The Two Brass Monkeys write about Tetrahedrane:
Tetrahedrane is an easy assembly puzzle, first designed and prototyped by Oskar van Deventer in May 2009.
It is, of course, our brass and stainless steel take on Oskar's 3D printed puzzle "Screwballs".
The puzzle has six identical stainless steel rods with right and left-handed threads at the end, and four different vertices, each with three threaded holes. The object of the puzzle is to assemble a tetrahedron.
The puzzle comes assembled and stands around 60mm tall when assembled and weighs around 120g
We felt we couldn't call our version of the puzzle Screwballs, as we have no balls and that name is a little bit risque for our liking. So we asked Oskar for his suggestion and he said:
"My suggestion for the name: Tetrahedrane Puzzle (https://en.wikipedia.org/wiki/Tetrahedrane). Tetrahedrane is a yet unsolved chemical mystery, so the name may be appropriate in multiple ways."