Why is it called a Monkey Wrench? Well some say it’s named for the man who invented it in the late 1800’s, Charles Monk, which has been debunked. The name Monkey Wrench for an adjustable wrench was already a common term by the time Charles Monk came onto the tool-making scene in the 1880s, never mind the fact that he made molders tools. One of the earliest patents for this style of wrench comes from Loring Coes, an inventor and industrialist in 1841, where it was already called a Monkey Wrench. They’ve also had a few different names like a wagon wrench, adjustable wrench and even The Ford wrench because from 1903-1904 one of these infamous wrenches came with the Ford Model A in a tool kit. So if this useful tool had been called so many things, where does the term Monkey Wrench come from? Back in the day, the nautical term “monkey” was used to describe a small piece of equipment or structure engineered to suit an immediate need. Considering the first few models of this wrench were made for wagons to be able to adjust to wheel size, it makes sense why it started out long ago as the Monkey Wrench.