On Sat, 26 Apr 2014 11:00:59 +0100, wrote:

I want a joint that can be flexed in two directions at right angles to
each other. In principle I could do this using two hinges with one
plate of one hinge fixed at right angles to one plate of the other.

Is there a 'ready made' piece of hardware that can do this? If so,
what is it called?

I don't want a ball joint because movement in all directions isn't
necessary and a ball joint generally won't allow 90 degrees (or more)
of flexion like a hinge.

The device I want would allow me to fix a bar to a surface and swing
it 180 degrees in two planes (at 90 degrees to each other).

Like a saloon door hinge? Sometimes called a cafe door hinge?

Nick