About Hinges

In the example shown, the two parts are free to rotate about the highlighted axis; all other rotations and deformations are restrained.

You can use a hinge restraint to model actual hinges in your model, as well as any other connections where a component is free to rotate about a single axis only, such as gears and wheels. The cylindrical surface you select as the hinge joint can rotate about its own axis, but it cannot deform in any other manner.