What Are Wrenches?

What is a wrench? To people familiar with this ubiquitous tool, it may sound like a stupid question, but in fact, not everyone has used a wrench, or knows what exactly one is or how it works, let alone the many different wrench types and what each is good for. Generally speaking, a wrench, also known as a spanner in British English, is a very useful moving tool that applies torque to fasten or loosen nuts and bolts.

Simple enough, but there are a lot of common wrench types, each designed with different purposes and uses in mind, and operating in different ways. Open-ended wrenches, for instance, are simple, one-piece tools with a handle and a U-shaped opening on one or both ends, designed to grab opposite ends of the nut or bolt. Most often, if both ends have an opening, they are different sizes for purposes of convenience. A type of open-ended wrench is the adjustable wrench, which has adjustable-size jaws. The most commonly recognizable kind of adjustable wrench is the pipe wrench, also known after its inventor as the Stillson wrench, often portrayed in movies, video games, and other popular media as a bludgeoning weapon.

Among the more modern types of wrenches, the impact wrench, also known as the air wrench, impactor, or torque gun, which is a powered tool that applies a high torque output but requires little physical exertion by the user. The impact wrench can be categorized under the wrench type known as a socket wrench, whose cylinder is applied over the nut or bolt head.

Wrenches can be constructed according to different standards of measurement, and both metric wrenches (those conforming to the metric system), as well as wrenches built according to the United States customary system, are quite common.

To find out more about torque wrenches, pipe wrenches and impact wrenches, check out the additional pages above!