Mechanical joint

It enforces a cylindrical contact area, which makes it a lower kinematic pair, also called a full joint.

A prismatic joint provides a linear sliding movement between two bodies, and is often called a slider, as in the slider-crank linkage.

[3] In an automobile, ball joints are spherical bearings that connect the control arms to the steering knuckles.

[5] A ball joint consists of a bearing stud and socket enclosed in a casing; all these parts are made of steel.

Motion-control ball joints tend to be retained with an internal spring, which helps to prevent vibration problems in the linkage.