Materials, Types, and Applications of an Essential Component for Structural Integrity

The technological and industrial development of the modern world has led to the invention of self-locking nuts, which today represents the most advanced solution to prevent loosening, misalignment, or decoupling of bolted joints. Self-locking nuts have a simple yet ingenious design: their functioning principle in based on creating additional resistance against unscrewing, which ensures a stable connection over time and thus the safety of the structure. These nuts exhibit great versatility and find varied industrial applications, especially in the automotive and aerospace sectors, where vibrations and solicitations, to which the structures are subjected, require absolute joint stability.

Self-locking nuts are easily recognizable due to a distinctive element that prevents unscrewing. This element can take various forms and materials based on the applications, ranging from nylon inserts—the initial type introduced—to more sophisticated solutions like integrated metal flanges and caps integrated in nut.

Nylon-insert self-locking nuts feature a nylon ring at the top, slightly smaller in diameter than the bolt. When a bolt is tightened against the nut, the insert elastically deforms over the threading, generating constant friction that tightens the grip and prevents unscrewing. This nut type, thanks to its excellent combination of safety and strength, is ideal in contexts where vibration resistance is crucial, particularly in the automotive and aeronautical industries.

 – Flanged self-locking nuts have an integrated flange that acts like a washer, distributing the load across the threads and reducing pressure exerted on the surface. The lower side of the flange can be smooth or equipped with radial serrations that further inhibit rotation and unscrewing. This nut type minimizes the risk of damage to metal components. Hence it finds application in situations requiring stable and lateral force-resistant connections, such as frames and load-bearing structures.

Blind self-locking nuts with caps feature a plastic or steel cap at the top. The domed end encloses excess threading, hiding it from view and protecting it against accidental impacts or contact. Despite their diverse uses, these nuts are often employed as covers for bolts and threaded bars, especially in cases requiring specific aesthetic attentions.

Fully metallic self-locking nuts are characterized by radial deformation of the threading: the diameter of the threading progressively reduces without altering the pitch. During the screwing process, a force is generated that creates friction on the thread, preventing the nut from losing adhesion. Before use, entirely metallic nuts require specific lubrication.

VIPA’s catalog offers all types of self-locking nuts available in the market, including the most specific ones or those made from the most resistant materials. They are all available for immediate delivery at VIPA’s warehouse, which, with over 70,000 references, is Italy’s most well-stocked. No matter the sector your company operates in, VIPA has what you need: visit the VIPA shop to select the most suitable fastening components for your requirements.