What Are Lock Nuts?

A nut is a common fastener used for numerous assemblies, typically being paired with a bolt for securing two or more parts together. While able to hold onto a bolt with their internal threading, nuts may loosen over time if exposed to vibration or torque. In instances where fasteners are at risk of becoming loose, a special nut known as a lock nut will commonly be implemented. Coming in a variety of types, lock nuts are special components that resist loosening under vibration and toque with the use of friction or positive locking devices.

Friction lock nuts are a commonly used type that take advantage of friction to resist loosening under various forces. As such, they often require more torque for installation and removal as compared to a standard hardware component. This can generally increase assembly time, though will ensure that such fasteners rarely are removed unintentionally. Positive locking nuts, on the other hand, only lock to their assembly when a positive action is performed. Before this, they can be rotated with ease for tightening and loosening, ensuring rapid installation and removal until the positive action is performed.

Depending on one’s needs, there are numerous common lock nut types that one may use, each of which differ in their capabilities and application. The hexagon nut, also known as a hex lock nut or jam lock nut, is a standard fastener type that resists loosening through having two nuts tightened to the assembly. With the second nut, the hex nut can be jammed against the standard nut to hold the assembly in place.

Nylon locking nuts are another common type, offering easy installation while remaining resistant to loosening. During installation, friction will cause the nylon insert to become heated and soft, thus permitting the accommodating screw or bolt to deform the thread. As the component cools down, the insert will harden around the assembly, locking it in place. This makes the nylon locking nut extremely secure on the assembly, though removal can be difficult due to the hardening of threading.

The castellated nut, or castle nut, is a type of positive locking nut that features nut slots on one end. With the cylindrical extension and notches, the nut may be assembled and secured with a pin that is inserted through the threaded shaft. This prevents the nut from becoming loose due to rotation, and the securing component may come in the form of a safety wire, cotter pin, or R-clip. Slotted nuts are fairly similar to the castellated nut, albeit having the notches cut into the flat face of the component.

Whether you decide that you need a bearing lock nut, crimper lock nut, extractor lock nut, hard lock nut, cap lock nut, or another variation, it is important to consider various factors prior to making a purchase. While one nut type may present optimal locking conditions, the material of the fastener can also have an effect on performance, sometimes even warranting risks of corrosion if one is not careful. Additionally, the nut should always be sized correctly to ensure that it can tighten onto a bolt or screw and accommodate the space of the assembly.

When it comes time to begin sourcing the various fasteners that you require for your operations, look no further than Aerospace Sphere. Aerospace Sphere is a premier supplier of aviation, NSN, and electronic parts, providing customers access to an unrivaled inventory of over 2 billion items. Upholding a strict NO CHINA SOURCING pledge, all of our inventory comes from leading global manufacturers that we trust and has undergone rigorous quality assurance testing. Get started on the purchasing process today with a competitive quote for your comparisons when you fill out and submit an Instant RFQ form as provided on our website.


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