Durable steel construction with long arm and ball end. The robust hex keys feature chrome vanadium steel construction for maximum strength and reliable performance, even under high levels of force. Heat treated with a black oxide finish, the tools resist corrosion, plus sand for an exceptionally smooth surface. Additionally, the long-arm hex keys offer extended reach for increased leverage and maximum torque, chamfered ends for easy insertion into the fastener head, and a ball-end design, which accommodates up to a 25-degree entry angle for easily reach obstructions. The precisely sized ends are chamfered to slide easily into the clasp, reducing wear on the keys and damage to the clasp head. Instead of layers of plating, the steel surface of each key is directly treated with a black oxide finish. Since this finish will not flake or peel, it will not damage your work or decrease the fine adjustment on closures over time. Optimal Strength: These Gothic tools are made with Eklind alloy steel that is heat treated, tightened and tempered for optimal strength, torque and ductility for added safety and coated with a corrosion resistant finish. Long arm design provides extended reach and increased leverage and torque; beveled ends ensure easy insertion. The ball design allows an entry angle of up to 25 degrees to easily reach obstructions.