Neiko 50432A Nylon Lock Nut Assortment Kit with Carrying Case, 150 Pieces | SAE Versatile assortment of 150 standard nylon lock nuts in 7 common SAE sizes for convenient all-purpose use most ideal for professionals and DIYers Nylon collar replaces lock washers preventing bolts from coming out for a more secure and durable hold High quality polymer-insert lock nuts resist turning, preventing nut from loosening under vibration and torque Extra sturdy compartmentalized plastic carrying case allows neat organization and convenient storage for any garage, work bench, or on the go job sites Wide range of uses included in kit comes with the following sizes: M5x24 (25 Ct), 1/4"x20 (35 Ct), 1/4"x28 (25 Ct), 5/16"x18 (30 Ct), 3/8"x16 (25 Ct), 1/2"x13 (10 Ct)