Description: These nylon inserted lock nuts can be used anywhere this size is needed. Nylon insert lock nuts are also known as stop nuts, and these nuts are used for fastening to a bolt when mechanically joining materials together. The bolt threads into the nylon material are located at the top of the nut. Nylon insert could prevent backing off or loosening from vibration. Features: These lock nuts are made from 304 stainless steel for durability and great corrosion resistance for outside use. Nylon insert lock nuts have a undersized nylon washer that creates friction with the mating threads to prevent loosening. There are total 7 different sizes of lock nut that you can choose for different bolts and use them in various situation. They can prevent vibration from loosening a bolted joint, resist loosening under vibrations and torque to provide a locking action. These lock nuts are amazing replacement for normal nuts of hardware, vehicles, home or outside applications. Specifications: Material: 304 stainless steel Standard: A2-70 Insert: Nylon Size & Quantity: M3 45pcs M4 35pcs M5 30pcs M6 25pcs M8 15pcs M10 10pcs M12 5pcs Box Size: 17.4 x 10 x 2.3cm / 6.85 x 3.94 x 0.91" Package Includes: 1 set x Lock Nuts