From the Manufacturer Eklind L-Keys are produced from the highest quality Elkind Alloy Steel. Eklind's superior quality provides maximum torque and prevents rounding out of the key or hex socket. OPTIMUM STRENGTH- These EKLIND tools are made with EKLIND Alloy Steel that is heat treated, quenched and tempered for optimum strength, torque and ductility for safety and coated with a rust resistant finish.