Allen wrenches are L-shaped metal tools designed for use with special screw heads. Unlike the sharp, narrow edges flat-head screwdrivers, the end of an Allen wrench is blunt with a hexagonal shape that fits into screws with hexagonal recesses. Often included with assemble-it-yourself furniture sets, Allen wrenches come in different sizes and may consequently be purchased in sets. This ensures that no matter what size screw you are working with, you have the Allen wrench you need to get the job done.
Insert different-sized Allen wrenches into the screw head recess to determine which one is the best fit. Insert the short end of the wrench to gain the most leverage.
Rotate the Allen wrench like a crank to drill the screw in or out of its hole. Rotate it clockwise to insert a screw and counterclockwise to remove one.
Hold the screw steady between your thumb and forefinger to keep it from wobbling and entering or exiting its hole at an angle. Rotate the Allen wrench slowly to keep it steady.