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Who Invented the Monkey Wrench?

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monkey wrench

Image credit: JTMultimidia, Pexels

Amazingly enough, the history of the monkey wrench is shrouded both by mystery and controversy. Hoaxes in recent years, amplified by the internet, have suggested various false origins for the tool.

One of those suggests that African-American boxer Jack Johnson invented the tool, and the racists of the time added the label “monkey” as a racial epithet. However, neither part of this story is strictly true. Johnson received a patent for improvements on already-existing wrenches. Consequently, the naming of the tool wasn’t racially-motivated.

Jack Johnson

Image credit: Bain News Service, Wikimedia

Another hoax suggests that a man named Charles Moncky invented the tool. Historians have found no record of a Charles Moncky living in the area at the time it is said, though researchers found multiple Charles Monks. However, none of the possible Charles Monks can be the inventor. All were children when the tool was invented or born after the term “monkey wrench” was already in circulation.

The circulation of the name is what makes identifying the inventor of the monkey wrench so difficult, as the term “monkey wrench” appears to predate the invention of the tool that we know today as the monkey wrench.

It appears that at least some people in the world were calling the carriage wrench a “monkey wrench” before the like invention of the latter in the 1840s. The early appearance of the term further complicates the problem, as we now have to consider the monkey wrench as a close relative of the carriage wrench. The naming confusion makes it hard to look back at historical documents and know for certain which tool the writer is referring to. Is it the monkey wrench as we understand it today, or the carriage wrench using the monkey wrench’s name?

So, our certainly is relatively low on this subject, but that doesn’t mean that we don’t have a good guess.

The apparent inventor of the monkey wrench is Loring Coes, who invented the tool in 1840 in Worcester, Massachusetts. That date is about 37 years after the earliest recorded use of the term “monkey wrench,” however we know that this time the name stuck to the tool Coes invented, as its design remained in production by various companies for the next 120 years.

Loring Coes

Image credit: William T. Davies, Wikimedia

The monkey wrench was an improvement over previous tool designs with similar functions, but unlike those, it only required one hand to operate, making it a more versatile tool.

While we still use the term today to refer to modern tools, we are in most cases using adjustable wrenches instead of monkey wrenches. Adjustable wrenches, which are sometimes called “crescent wrenches” in the United States, and “Bahco wrenches” in Europe, move the screw from the side of the wrench to a central location beneath the movable jaws.

The redesign lowers the force needed to adjust the tool, and also allows the same functionality to shrink into a smaller form.

So, while we can’t say with full confidence that we know the full origin story of the monkey wrench, if someone ever asks you about its origin, you should say: Loring Coes invented the monkey wrench in 1840 in Worcester, Massachusetts.

About the Author Adam Harris

Hi there! My name is Adam and I write for HealthyHandyman. I have a great passion for writing about everything related to tools, home improvement, and DIY. In my spare time, I'm either fishing, playing the guitar, or spending quality time with my beloved wife. You'll also often find me in my workshop working on some new project!