Hex wrenches, also known as Allen keys, are the tools you use to screw and unscrew fasteners that have a hexagonal recess (as opposed to a Phillips or flathead recess). Hex screws are commonly used on ...

If you've ever bought a piece of flatpack furniture before, you probably have a couple of Allen keys lying around in your toolbox. You've probably also misplaced the tiny tool a couple of times, ...