Why Do We Call It a “Stillson Wrench”?

While there are endless varieties of tools, the wrench is particularly versatile. Need an adjustable wrench for tightening nuts? You might want a Crescent wrench. Want something that can tackle industrial projects like automobiles? You can grab a monkey wrench. Want to put together an IKEA bookshelf? An Allen wrench works.

If you have a plumbing issue, however, you’re likely to turn to the wrench that can sink its literal teeth into pipes. That’s a pipe wrench, also known as a Stillson wrench. And while all tools have pushed manufacturing forward, the Stillson stands out as one of the most important developments to ever grace a toolbox.

1. The Origin of the Stillson Wrench
2. A Wrenching Victory

The Origin of the Stillson Wrench

Daniel Stillson had a way with machines. The Durham, New Hampshire, native was a mechanic on a U.S. Naval steamship, the R.B. Forbes, for the Union during the Civil War. Afterward, a Union engineer and colonel named Levi Greene invited him to come work for him at J.J. Walworth and Co., a steam heating business in Cambridge, Massachusetts. It was at Walworth that Stillson would make his mark on tool history.

According to a 2019 Boston Globe article, in the late 1800s, cities were making a push to install and maintain water systems for indoor plumbing and heating. Some, like Boston, had to replace older wooden pipes with materials that were more sensible for the reliable transportation of water. As this transition to metal occurred, it was obvious that not all existing tools were up to the challenge.

The biggest problem for monkey wrenches and other types of clamping tools was that their jaws were usually smooth. That worked for fasteners like nuts, since one flat surface could sit flush with another, but it didn’t work well for pipes. Their round surface meant flat wrenches could—and often would—slip off or damage the pipe.

Stillson certainly wasn’t the first engineer to observe the problem, but he was the first to take real action. His first solution was a kind of tong that could better grip the pipe but still proved less than ideal. Using wood, he carved out a prototype wrench that had a slightly uneven, serrated surface. Because the “teeth” ran opposite one another, they had a fierce grip that was able to keep a secure hold on round, slippery metal pipes.

When Stillson showed his idea to Greene, the company agreed to have a steel version made. Greene wanted to see if it was as strong as Stillson claimed and encouraged him to attack a pipe until either the metal broke or the wrench did. After he successfully tore into a 1.25-inch pipe, Greene was convinced. Stillson’s wrench worked.

Though they likely could have claimed Stillson’s invention as their own owing to his employee status, Walworth encouraged him to patent it under his own name. The company would then license it from Stillson so it could be manufactured and distributed to consumers.

Stillson went ahead and filed a patent application for the wrench in 1869, which was granted in April 1872.

“I, Daniel Stillson of Charlestown, in the county of Middlesex and state of Massachusetts, have invented a new and useful improvement in pipe wrenches,” he wrote. “My invention is an improvement upon the pipe wrench as patented by me … and has for its object the production of a wrench which shall be equally effective in its operation upon a pipe, whether such pipe be perfectly cylindrical or circular, or of a somewhat flattened or ellipsoidal shape in cross-section; and my invention consists in the employment of two springs affixed to opposite sides of the shank of the fixed jaw, and so arranged as to operate in conjunction with the pivoted frame in controlling the action of the movable jaw, as will be hereinafter described.”

A Wrenching Victory

Plumbers, mechanics, and even locomotive workers grabbed the wrench, which was, like the monkey wrench, adjustable and could therefore replace cumbersome wrench sets.  

Walworth even displayed Stillson in advertising, crediting him as the inventor of the wrench—a somewhat unusual marketing approach. A print spot from 1928 showcases a Stillson said to be 37 years old and still working. “That is the kind of lasting strength you can count on getting in any wrench of any size that carries Dan Stillson’s own trademark—STILLSON—forged in a diamond on the top jaw,” the ad read.

Though the patent would ultimately expire, Stillson benefited greatly from Walworth’s lack of greed. At the time of his death in 1899, Stillson had made an estimated $100,000 from the wrench, or well over $3 million today. And although anyone is free to make a Stillson-style wrench and name it anything they like, Stillson’s influence is such that people often refer to it using his surname.

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