The head set for a pair of forks on a bike/motorbike.
chain
spa75:The head set for a pair of forks on a bike/motorbike.
garyk49:chain
It's not bike forks headset or a chain.
Rocker mechanism for a recliner chair or sofa
It's not a rocker mechanism Lesley.
I'm stumped, so thinking just on description about most owning one possibly more,
A watch (clasp)
Kitchen cupboard hinge
Some of your guesses have been warm, but it's neither a watch clasp or a kitchen cupboard hinge.
Brass bushing in a cylindrical hole.
That might be what you see irzy, but it's not the whole object. : )