Mole grips/locking pliers work in the following way:
Gripping an object
The upper handle and jaw of Mole grips/locking pliers is fixed, while the lower handle and jaw is moveable and adjusts to accept different sizes and shapes of objects.
When the two handles close together around an object, you should hear a “click”, which indicates that the pliers have locked.
The jaws can then be manually adjusted to ensure a tight grip, by turning the adjustment screw in the upper handle.
Leverage
Mole grips/locking pliers use levers (the handles) and multiple pivot points to expand and contract the jaws in direct proportion to the amount of force applied to the handles.
This means that they are able to mechanically multiply the force applied to the lever by as much as tenfold.
Releasing an object
The release lever opens the handles; the user either depresses the lever, or pulls it upwards on Mole grips/locking pliers with an extended release lever.
The release lever pushes against the link bar which pushes the handles apart. This action eases the pressure of the jaws from around the object.
Mole grips/locking pliers are suitable for both right and left-handed use.
Most Mole grips/locking pliers require a two-handed operation to adjust them, lock them into place and release them. (See: How to use Mole grips).