Products + Tools

Locking nuts and washers have vital roles in securing fasteners, helping to prevent loosening due to vibration, thermal expansion or dynamic loads in various industries where safety and reliability are paramount. Here Norm Fasteners highlights the different types of locking nuts and washers it can supply, as well as the applications they can be used in.

Norm Fasteners is able to supply a wide range of locking nuts and washers including:

• Prevailing torque nuts with nylon ring – these nuts have a nylon collar that grips the bolt threads and increase friction. This offers reliability, reusability and consistent locking performance, however they are temperature sensitive and therefore less effective in high vibration or high temperature environments. 
• All metal prevailing torque nut – this nut is deformed from either the sides or the top to maintain a constant torque by gripping the counterpart threads. It is effective in high vibration settings but requires higher installation torque, which may cause thread damage during applications with repeated use.
• Jam nuts – these thin nuts are tightened against a standard nut to lock both in place by applying opposing forces. These nuts are simple and cost-effective but require precise installation and can loosen if not properly tightened. 
• Serrated flange lock nuts – these nuts possess serrations or ripp on the mating surface of the flange with the counter part. The serrations bite into the surface to prevent loosening, distributing the load over a larger area to allow for reliable fastening. However, they can damage the surface coating and are not suitable for soft materials that can easily be damaged by the serrations.
• Slotted nuts – also known as castellation nuts, they have slots on one end and are used with a cotter pin that passes through a hole in the bolt – which subsequently locks the nut in place. With a highly secure locking mechanism, these nuts are used in critical applications such as automotive and aerospace. The downside is they require drilling a hole in the bolt,they are expensive and they have a long installation process.
• Locking washers – this includes split lock washers, tooth lock washers, flat washers and wedge lock washers. Split lock washers have a helical shape that grips the nut and surface, whereas tooth lock washers, with internal or external teeth, prevent rotation by biting into surfaces. Flat washers distribute loads and can complement other locking methods, while on the other hand, wedge lock washer pairs have outer serrations to grip surfaces and interlock with mating serrations inside. Lock washers enhance locking capability of standard nuts and are easy to install, while wedge lock washers exhibit a very high vibration and dynamic load resistance that makes them suitable for many industries. However, these washers may cause surface damage during application. In environments that are subject to high vibration, standard washers are less effective than specialised lock nuts. 

The future of locking nuts and washers is centred on enhancing performance and adaptability through advances in materials science. New high strength, lightweight materials are expected to improve performance in extreme conditions. 

Other trends include emerging smart locking systems that integrate sensors and IoT technology for ‘real time’ monitoring and adjustment. These innovations aim to overcome current limitations like temperature sensitivity and reusability, offering more reliable solutions for critical applications.