The Hillman Group 180180 Nylon Insert Lock Nut, 5/16-Inch by 24-Inch, 100-Pack Product Description The Nylon Insert Lock Nut features an integrated nylon insert that grips bolts to help resist vibration effects. This easy-to-use nut is ideal to securely fasten a bolt when connecting materials. From the Manufacturer The Nylon Insert Lock Nut features an integrated nylon insert that grips bolts to help resist vibration effects. This easy-to-use nut is ideal to securely fasten a bolt when connecting materials. Features Nylon provides better capability of providing renewed locking action after removal and re-installation Use for fastening to a bolt when mechanically joining materials For general applications Country of Origin: China USA SHIPPING estimates delivery times and we work to get your item to you as quickly as possible and within those times, but please know it may take slightly longer than the estimate.