A ball joint with a maximal angle of about 50 degrees. Connecting the ball to the socket is done with a clip, which also makes it easy to take it apart again. This ball joint is meant to be used in the woodworking world, the ball and the socket each have a hole for a countersunk wood screw.
You want to print this ball joint with 100% infill. You do not need supports.
Update: Added a stronger version of the clip and the socket. These need to be printed with supports (build plate only).