Hex Locknut Assortment Hex Type Standard Hex Includes Washers No Largest Thread Size 1/2 in-13 Lock Type Nylon Insert Number of Nuts 150 Number of Thread Sizes 6 Number of Washers 0 Nut Finish Zinc Plated Nut Material Steel Nut Type Hex Lock Nut Smallest Thread Size 1/4 in-20 System of Measurement Inch Thread Sizes #10-24 1/2 in-13 1/4 in-20 1/4 in-28 3/8 in-16 x 9/16 in 5/16 in-18