The STANLEY Long Hex Key Set 9 pc. is crafted from GGG-K-275D S2 steel, hardened to HRC 60 ± 2 for exceptional durability. Its fine satin finish enhances grip and corrosion resistance. Engineered to deliver 20% higher torque compared to standard Cr-V keys, this set ensures superior performance and reliability for demanding applications. Ideal for professionals seeking precision and strength in their tools.