The Different Types of Lock Nuts: A Comprehensive Guide

Lock nuts are fasteners used to secure bolts or screws in place by providing resistance against loosening due to vibration or external forces. They come in various designs and types, each offering unique locking capabilities. Here are some common types of lock nuts:

1. Nylon Insert Lock Nut

Nylon insert lock nuts, also known as nyloc nuts, have a nylon insert located at the top of the nut’s internal threads. When the nut is tightened onto the bolt or screw, the nylon insert creates friction and applies a prevailing torque, which helps prevent loosening. Nylon insert lock nuts are reusable and commonly used in a wide range of applications.

2. All-Metal Prevailing Torque Lock Nut

All-metal prevailing torque lock nuts, also known as prevailing torque nuts or stiff nuts, have a deformed or distorted top section. This deformed section acts as a prevailing torque feature, which provides resistance against loosening caused by vibration or rotation. All-metal prevailing torque lock nuts are durable and suitable for applications that require high vibration resistance.

3. Center Lock Nut

Center lock nuts, also known as crown nuts or slotted nuts, have a radial slot cut into the top section. This slot allows the nut to deform when tightened onto the bolt or screw, creating a mechanical lock. To secure the center lock nut, a cotter pin or wire is inserted through the slot and the bolt or screw, preventing rotational movement and loosening.

4. Castle Nut

Castle nuts, also known as castellated nuts or cotter pin nuts, have notches or slots cut into the top section. These notches are aligned with the hole drilled in the bolt or screw, allowing the insertion of a cotter pin or wire. The cotter pin prevents the castle nut from rotating, ensuring that the nut remains in place and resists loosening.

5. Serrated Flange Nut

Serrated flange nuts, also called serrated face nuts, have serrations or teeth on the bearing surface of the nut’s flange. When tightened, the serrations bite into the mating surface, providing resistance against rotation or loosening. Serrated flange nuts are commonly used in applications where a wide bearing surface is required, such as automotive and machinery assemblies.

6. High-Temperature Lock Nut

High-temperature lock nuts are designed to withstand extreme heat and thermal expansion. These nuts are made from materials such as stainless steel or specialized alloys that can maintain their locking properties under high-temperature conditions.

These are just a few examples of the types of lock nuts available. Each type is designed to provide specific locking capabilities and is suited for different applications and load requirements. When selecting a lock nut, it’s essential to consider factors such as the type of fastener, material compatibility, load requirements, and environmental conditions to ensure proper locking and prevent fastener failure.