Popular Mechanics; Courtesy Crescent Along with a hammer, tape measure and screwdriver, a crescent wrench is an essential part of any well-rounded toolkit. These handy tools have two jaws—one stationary and one that can be moved back and forth—allowing you to adjust the size of the wrench’s opening to fit a wide range of fasteners. This means that a single crescent wrench can essentially do the job of an entire set of fixed wrenches. Crescent wrenches almost always have size markings on the jaw itself, making it easy to set the correct size before you get to work. We’ve personally used our crescent wrench as a caliper as well, using…