What feature of a vise grip allows it to lock onto objects securely?

The locking lever is the feature of a vise grip that enables it to securely lock onto objects. When the locking lever is engaged, it triggers a mechanism that clamps the jaws of the vise grip together, creating a tight grip on the material or object being held. This design is crucial because it allows the user to apply consistent pressure without having to manually hold the handle, enhancing the tool's effectiveness for various tasks.

The adjustable jaws, spring mechanism, and metal construction of the vise grip contribute to its overall functionality and durability, but it is specifically the locking lever that provides the capability to lock and secure items firmly in place. This feature is what distinguishes vise grips from other types of pliers, making them essential for tasks that require stability and strength.