I built this screw to test how small I can get with threads on my 3D Printer. It turned out to be kind of fun to play with since it is a single 3DPrint and spins very easily.
A friend called it a "Gravity screw" when he printed it so I I thought I'd keep the name (thanks Deelip!). He did a video too.
My wife wanted me to make a Keychain version so I put a hole on the top. If you print at 1/2 scale, you can put a key ring on it.