There are many types of pliers. The most commonly used are the 6-inch combination slip-joint pliers. The slip-joint permits the jaws to be opened wider at the hinge pin for gripping large diameter objects. Some combination pliers are made with a side-cutter arrangement for cutting wire.
Pliers are often misused as general-purpose tools. Their use should be limited to operations for which they were designed: gripping and cutting (never for loosening or tightening nuts). Always use wrenches on nuts and bolt heads, never use a pliers. In fact, don’t use pliers when any other tool will do.
Pliers should not be used for bolt turning work for three reasons.
When cutting with pliers, the inside of the cutting jaws should point away from the user’s face in order to prevent injury from flying cuttings.
For a firm grip with minimum effort, pliers’ jaws should be as nearly parallel as possible. Using the right size pliers and proper positioning makes this possible.
To avoid overloading cutting pliers, the user should select the pliers with which he can cut a wire using only one hand.
Pliers, like all other tools, should be kept clean. Put a drop of oil on the joint pin, and keep the nut snug.
Like regular pliers, vice grip type pliers should not be used on nuts or bolt heads designed for a socket, box or open end wrenches.
The adjusting bolt and hinge pins should be lubricated to prevent rusting and locking up. These precautions cut down the wear and prevent rusting which is a vicious enemy of all tools.