Adjustable wrenches are versatile handtools. The wrench jaws are adjustable to fit almost any size bolt or nut. The lower jaw of the adjustable wrench moves up and down using the spiral adjuster on the tool handle. Grime and rust on the adjuster can make it difficult to rotate and can even cause it to lock up. The best way to unlock an adjustable wrench when this happens is to remove the grime, dirt and rust that is causing the problem.
Wipe the spiral adjusting mechanism with a rag to attempt to remove surface dirt. Attempt to rotate the adjuster as you wipe it down.
Spray the adjuster with a penetrating lubricant, ensuring that you spray at both ends of the adjuster. Allow the lubricant to soak into the adjuster to loosen caked on grime as well as rust.
Remove the excess lubricant with a rag and attempt to move the adjuster. If necessary, leave the rag over the adjuster and grab the adjuster with a pair of pliers. Turn the adjuster with the pliers to break loose any sediment locking the adjuster.