Locking pliers, Mole grips (Mole wrench) or Vise-Grips are pliers

Pliers

Pliers are a hand tool used to hold objects firmly, for bending, or physical compression. Generally, pliers consist of a pair of metal first-class levers joined at a fulcrum positioned closer to one end of the levers, creating short jaws on one side of the fulcrum, and longer handles on the other...

 that can be locked into position, using an over-center

Tipping point (physics)

A tipping point is the point at which an object is displaced from a state of stable equilibrium into a new equilibrium state qualitatively dissimilar from the first.- In electric power :...

 action. One side of the handle includes a bolt that is used to adjust the spacing of the jaws, the other side of the handle (especially in larger models) often includes a lever to push the two sides of the handles apart to unlock the pliers. "Mole" and "Vise-Grip" are trade names of different brands of locking pliers.

Locking pliers are available in many different configurations, such as needle-nose locking pliers, locking wrenches, locking clamps and various shapes to fix metal parts for welding. They also come in many sizes. Leatherman

Leatherman

Leatherman is the trade name for a line of multi-tools, knives and LED flashlights manufactured and marketed by Leatherman Tool Group of Portland, Oregon, USA.-Company history:Timothy S...

 manufactures a multitool, the Leatherman Crunch, which includes locking pliers instead of regular pliers, and which folds together to the size of other multitools.

Operation

The jaws are set to a size slightly smaller than what is to be gripped by turning the bolt in one handle with the jaws closed. When the jaws are opened and the handles squeezed together, they move a lever over its center point and lock the jaw of the pliers onto the gripped object. A typical usage would be to hold metal parts in place for welding

Welding

Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material that cools to become a strong joint, with pressure sometimes...

.

History

The first locking pliers, named Vise-Grips, were invented by William Petersen in De Witt, Nebraska

De Witt, Nebraska

De Witt is a village in Saline County, Nebraska, United States. The population was 513 at the 2010 census. The town was incorporated by the Nebraska Territorial Legislature in February 1857.-Geography:De Witt is located at ....

 in 1924. Mole grips were developed by Thomas Coughtrie

Thomas Coughtrie

Thomas Robb Coughtrie was credited by the Times as the inventor of the Mole wrench.However, this conflicts with other references that show the invention of the Vice Grip in Nebraska with an initial patent in 1921 and fuller developments patented in 1924. It could be surmised that M. K...

in 1955, then managing director of M. K. Mole and Son.

External links

• History of the Vise-Grip
• "New Tool Is Both Pliers And Wrench" Popular Science, December 1935, middle of page 42
• "Wrench With Vise Like Grip Keeps Work From Slipping" Popular Mechanics, September 1935 middle-left of pg. 326