An Allen wrench, AKA an Allen key or hex key, is a small hand tool used to fasten screws or bolts with a hexagonal socket. Either end usually works, although some sets only have one end.

They're so named because you need an Allen wrench (aka an Allen key or hex key) with a hexagonal socket to tighten them. The hexagonal shape provides six points to apply pressure to the fasteners ...

EASY TO PICK: Supplied in composite case for safe storage and quick key selection. Each wrench for quick size selection and easy organizing.