High Strength Alloy Steel Hex Wrenches with Limited Lifetime Manufacturer Warranty: Our Hex key set is made of high quality hardened heat-treated tool steel. Coated with black oxide, our hex key set easily stands up to the harshest environments.8 Piece Hex Wrench Set: From standard micro hex wrenches to metric allen keys, we’ve got you covered. SAE: T9, T10, T15, T20,T25, T27, T30, T40Compact Design: We designed our folding allen wrenches sets to be as compact and light weight as possible.