The term "monkey wrench" dates back to 1807 in Great Britain. Referring to the tool, the phrase appears in E.S. Dane’s "Peter Stubs & Lancashire Hand Tool Industry" catalog, which reads "Fleetwood, Richard...Parr, Rainford. Screw plates, lathes, clock engines...monkey wrenches, taps."
In 1858, Charles Moncky of Baltimore, Maryland, applied for a patent for the monkey wrench. Some believe the term monkey wrench is a derivation of Mr. Moncky's name, but its use in Great Britain in 1807 negates this assumption.
The phrase "throwing a monkey wrench," meaning the creation of an obstacle, dates to a 1907 article in the Chicago Tribune, which reads: "It should look to them as if he were throwing a monkeywrench..."