M3 Nyloc Hex Nut

Unlike conventional fasteners, lock nuts, sometimes known as self-locking nuts, contain a plastic insert that deforms to the thread of the fastener and prevents loosening without the aid lock threading adhesive. As such, they are often used where security in fastening is required. They are useful when joining soft materials such as wood and plastics where high surface pressure might damage the material, or when there is a short clamp load. However, their principal advantage is in applications where there is a high degree of vibration. Locking nuts resist loosening over time in dynamic load conditions.