Steel: 31CrV3 47—52 HRC Chroming H: 80 mm Length: 245 mm An angle wrench hex key (also known as an "Allen key") is used for working with fasteners that have an internal hexagonal socket. Angle wrenches combine two levers in their design: an extended lever for maximum force application and a short lever for quick rotation, and are also used when working with fasteners in confined spaces. The high strength characteristics help prevent damage to the edges of the fasteners. You can also purchase a set of hex keys.