'Machine Key, Undersized, Square End Type, Steel, Plain Finish, 1/2 In Length, 3/16 In Square, -0.002 In Thickness Tolerance, -0.030 In Length Tolerance, Tensile Strength 64, 000 PSI, Rockwell Hardness B85, Holds Pulleys and Gears on Transmission Shafts, Package 10'