The first adjustable wrench was invented by English engineer Richard Clyburn in 1842. Then known as an English key, or adjustable spanner, the design was improved upon by Johan Petter Johansson and marketed by the Bacho company of Sweden in 1892.
The Cooper Tool Company marketed its version of the adjustable wrench in 1907. The wrench was well suited for brake and clutch tuneups on automobiles of the time.
Cooper's brand name for the hand tool was Crescent, and the name has become synonymous with any adjustable wrench.
The Crescent wrench can be adjusted to fit a variety of nuts and bolts. This versatility allows a single adjustable wrench to replace an entire set of fixed wrenches.
Modern versions of the Crescent wrench include a locking mechanism to set the movable jaw in the appropriate position. Further technological advances include digital models that indicate when the nut or bolt is fully tightened.