Pliers pinch and grip; wrenches use leverage to help twist. But what if you want to do both at once? Well, have no fear, science is here!
A plier wrench, aka mole grips, vise grip wrench, and self-grip wrench, have two arms that move freely in the same way as a pair of pliers, grip the same as a pair of pliers, but are designed to
be sturdy and comfortable to be held tightly in one hand when exerting significant leverage against whatever they are holding, like a wrench.
As a matter of course, they tend to be adjustable. The traditional way of achieving this is in the same manner as slip-joint pliers, in which the pivot can be adjusted into different positions along the wrench to allow for wider and narrowing openings. Many newer plier wrenches use a knurled nut to give fine control over jaw closure; these modern designs also tend to a spring loaded "lock" that will keep the tool firmly closed until a release lever, located inside the lower arm, is pulled. While both types have their benefits, the modern locking plier grip, often called a vice grip, is a particularly useful tool to have in your tool box.