A circular manual control device that provides mechanical advantage for opening valves, adjusting machine tool feeds, or setting tension. The diameter of the wheel dictates the torque a human operator can apply to the attached stem or leadscrew. They often feature a knurled rim or a spinner handle for rapid turning.
Heard on the job
Give that handwheel another quarter turn to choke the flow.
Insider tip
If a handwheel requires a cheater bar to turn, the valve stem is likely seized and needs maintenance, not more force.