Allen wrenches are undeniably useful, but they can also cause headaches. They’re slender, which doesn’t leave a lot of room for easy-to-read size markings, and they’re easy to drop, particularly when ...

At first glance the Allen wrench doesn’t seem to be much of a tool. It’s little more than a small, L-shaped piece of metal. But don’t be fooled by its humble appearance, the Allen wrench is an ...