All About Lock Wires

From aerospace to automotive applications, lock wires are typically employed within assemblies to prevent fasteners and connections from loosening as a result of vibration, thermal expansion, or other external forces. In this blog, we will explore the basics of lock wires, providing a brief overview of their types, applications, and installation techniques.

Lock wires, also known as safety wires, are thin, strong lengths of metal material that are tightly wound around fasteners or components to prevent them from coming loose after installation. They provide an additional level of security to these critical connections, reducing the risk of accidents or failures that come from fasteners falling out of an assembly. In order to best sustain integrity in the face of corrosive environments, many lock wires are made of stainless steel or other high-strength alloys.

There are two main types of lock wires that are used: double-twist wire and single-wire variations. Double-twist wires, as the name suggests, consist of two wires that are twisted together. This configuration provides a high level of security for fasteners, as it requires more effort to unwind the wire when compared to single-wire alternatives. Double-twist wires are commonly used in high-stress applications where extreme vibrations or dynamic loads are present. Within the aerospace industry, double-twist lock wires are crucial for securing critical components, such as engine parts and control surfaces.

On the other hand, single-wire locks are those with a single strand of wire wound around a fastener or component. Single-wire locks are easier and quicker to install compared to double-twist wires, and they are frequently employed in applications that require less stringent security while still maintaining reliability. Automotive, manufacturing, and industrial equipment are all areas where single-wire lock wires find extensive use.

Now that we have covered the two common types of lock wires, we can now discuss the installation process for both. Proper installation is crucial to ensure the effectiveness of lock wires, and here are the general steps involved:

Start by selecting the appropriate lock wire size and material based on the application in question. For many general-purpose needs, stainless steel lock wires are a good choice due to their excellent strength and corrosion resistance.
Clean the fastener or component thoroughly to remove any dirt, grease, or oil. This step ensures a secure grip for the lock wire.
Position the lock wire in such a way that it wraps around the fastener or component and then crosses over itself. This crossing point is crucial for creating tension and preventing unwinding.
Using a lock wire tool or pliers, twist the wire tightly in the appropriate direction. The tightness of the lock wire is essential to maintain the desired tension.
Once the wire is twisted, cut off any excess length and secure the loose end by bending it tightly against the fastener or component.
Finally, inspect the installation to ensure that the lock wire is correctly positioned and tightly secured. Any loose or improperly installed lock wires should be immediately corrected.

When purchasing lock wires, it is important to note that they can be subject to certain regulations and guidelines, particularly in safety-critical industries like aviation. For instance, the Federal Aviation Administration (FAA) has established specific requirements for lock wire installation and maintenance in aircraft. As such, it is essential to adhere to these regulations and follow industry best practices to ensure the safety and reliability of lock wire installations.

If you are interested in procuring top-quality lock wire solutions for your various operations, we have you covered here on NSN Fulfillment. Owned and operated by ASAP Semiconductor, we present customers access to over 2 billion new, used, obsolete, and hard-to-find products that trace back to thousands of leading manufacturers that we trust. As you peruse our online selection, be sure to fill out and submit an RFQ form for any items of interest that you come across. Using offered information such as your target price and expected shipping time frame, we will best formulate a solution that closely caters to your individual needs and restrictions alike. You can also give us a call or send us an email at any time to directly connect with our team, and we would be more than happy to assist you however we can as your strategic sourcing partner!