"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." Hex wrenches, also known as Allen keys, are the tools you use to screw and unscrew fasteners that have a ...

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 ...

This conventional double nut has a split spacer that can be removed for grinding to adjust the preload. Fitting keys prevent the nuts from turning relative to each other. The size of the nuts, mainly ...