What Is a Hi-Lok Fastener?

Hi-Lok fasteners are a common aerospace component, coming in the form of a two-piece fastening assembly. As an all-purpose fastener, Hi-Lock components are regularly relied on for the construction of various aviation assemblies as a result of their ability to establish consistent torque on every fastener. In this blog, we will discuss the functionality and use of the Hi-Lok fastener, allowing you to better understand how it compares to other various options.

Hi-Lok fasteners are considered to be a type of pin, and they are capable of being installed from one side of an assembly by a single individual. While providing consistent torque during installation, a regulated breakoff groove featured on the collar ensures that the fastener is able to be self-locking as uniform preload values are achieved during separation. As a result of this action, every Hi-Lok fastener guarantees a controlled preload that leads to less fatigue being induced on the airframe. When compared to an alternative fastener, such as a swaged collar type system, Hi-Lok fasteners significantly improve the service life of an aircraft assembly with high tensile strength for increased reliability in extreme environments. Coupled with creating uniform preload values, the breakoff feature also minimizes the need for torque inspections, leading to increased dependability and efficiency.

When searching for such fasteners on the market, one may come across what is known as a Hi-Lite pin. These pins are the predecessor of the Hi-Lok fastener system, and they are regularly used for clearance or low interference fits in aviation applications. As such, they may be found in the assembly of wings, the fuselage, engine fairings, and much more. If a Hi-Lite pin is coupled with matching nuts and collars, they can achieve weight savings that surpass previous generations.

Hi-Lok fasteners are a branded product, produced by Hi-Shear corporation. With their design, they are primarily intended for structural joints where shear loads are taken on. For measuring such fastener components, one should use the Hi-Lok Grip Gauge and Slide tool. The tip of the gauge can be slid through a hole, and the gauge should be drawn back until the backside of the hole is met. Then, the necessary length of the Hi-Lok fastener can be determined. Typically, Hi-Lok gauges allow for measurements to be found in terms of inches and millimeters.

Beyond measurements, there are also multiple standard configurations of Hi-Lok pins, each of which may differ in their material, maximum temperatures, head style, and more. For example, pins may be made from titanium, alloy steel, aluminum, or other various substances, and each will determine their compatibility with other materials and temperature ranges. Then, head types range from protruding shear heads to reduced flush shear heads, each of which exhibit different shapes. When it comes time to begin sourcing all the Hi-Lok fasteners, Hi-Lite pin components, and other fastening systems that are necessary for optimally carrying out your objectives, let the experts at Aviation Store Online help save you time and money.

Owned and operated by ASAP Semiconductor, we offer customers access to an unrivaled inventory of over 2 billion new, used, obsolete, and hard-to-find parts that have been sourced from leading global manufacturers that we trust. With AS9120B, ISO 9001:2015, and FAA AC 00-56B accreditation, we go above and beyond industry standards to ensure that customers always receive high-quality parts they can rely on. Furthermore, we also uphold a strict NO CHINA SOURCING pledge, meaning that every ordered item ships out alongside its applicable qualifying certifications and manufacturing trace documentation. Get started today and see how Aviation Store Online can fulfill all your requirements with time and cost savings.


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