Allen Key Set USA Sizes. American sizes; 13-piece set; With black ProGuard ™ finish. Includes .050, 1/16, 5/64, 3/32, 7/64, 1/8, 9/64, 5/32, 3/16, 7/32, 1/4, 5/16 and 3 / 8 inches. With ordinary hexagon and hexagon with ball valves. The ball end of these US-made Protanium ™ industrial high torque steel hex keys allow you to work in hard-to-reach places at a maximum angle of 25 °. Comes complete with plastic holder.