News
HEICO – Bolt locking technology for maximum safety in defense applications:
Mission-critical environments demands absolute reliability at every level of engineering.
From military vehicles to weapon systems, components are subject to extreme mechanical stress and continuous dynamic forces. Under these conditions, self-loosening of bolted joints can escalate into catastrophic failure. In the field where maintenance opportunities are limited and failure carries significant consequences, reliable fastening solutions are essential to maintain performance, safety and mission success.
The risk of bolt failures due to self-loosening caused by vibration and dynamic loads is often frequently underestimated. In dynamically loaded assemblies - like in military vehicles, weapon systems, or aerospace defense applications - the absence of effective locking systems can lead to gradual preload loss and subsequent self-loosening of bolted joints. HEICO-LOCK® Wedge Locking Systems offer various and reliable solutions that prevents self-loosening by maintaining bolt preload forces.
HEICO-LOCK® offers a wide range of innovative bolt locking devices and combination products that covers even the most demanding applications. All products from this series are based on the proven wedge locking principle. The functional principle relies on a two-washer system with radial ribs on the outer surfaces and opposing wedges on the internal surfaces. During tightening, the outer radial ribs imprint into both the underside of the bolt head or nut and the bearing surfaces of the components, creating a locking interface.
The inner surfaces consist of wedges arranged in opposing orientation. When the joint is subjected to transverse vibration or dynamic shock loading, any tendency for rotational loosening results in a relative displacement between the washer pairs. Due to the angle of the wedges being greater than the thread pitch angle, this displacement is converted into a slight increase of the clamping force rather than a loss of preload.
This is how the HEICO-LOCK® wedge locking washer system ensures that any tendency toward self-loosening is actively counteracted by the geometry of the system itself, maintaining the clamp load stability even under extreme dynamic operating conditions.
Unmatched diversity in bolt locking solutions for secure connections
In addition to the established wedge lock washers, the German HEICO Group provides a variety of smart product variants and combined fastening solutions - for every application requirement.
The HEICO-LOCK® Combi-Washers offer significant advantages in terms of handling and field usability. The integrated inner plastic ring with small internal tabs enables the washers to be attached easily onto any standard bolt type. This also allows the pre-assembly of bolt and washer.
From an operational perspective, this simplifies the assembly process considerably and reduces the installation time under field conditions. A real advantage in military and maintenance scenarios, where rapid component replacement and high operational readiness are essential.
The HEICO-LOCK® Wedge Lock Nuts, a captive combination of a nut and a wedge lock washer pair, also provide distinct handling advantages. By integrating the locking element directly into the fastener, installation is simplified and the risk of assembly mistakes can be reduced. In M14x1.5 - M24x1.5 and 7/8“-11 BSF, this product solution is suitable for wheel fastening applications, providing reliable security for on-road and off-road vehicles.
HEICO-LOCK® and operator safety are aligned - even when using powerful high-torque tools
With the new Reaction Washers, HEICO revolutionizes the tightening of large bolted joints by the use of electric, hydraulic and pneumatic high-torque tools. From nominal size >M24, the required tightening torque typically exceeds what can be applied manually. In these cases, high-torque tools are used for installation and maintenance. Increasingly, high-torque tools are also applied to smaller dimensions, such as M16, particularly where large quantities of identical fasteners are installed.
Conventional high-torque tools require reaction-arms or mounts to absorb counteracting forces during tightening. This force is transferred to surrounding components to stabilize the tool. Despite these supports, serious pinch-point safety risks remain for the worker, e.g. hand injuries, crushing hazards, and tool slippage - even for experienced operators.
The new Reaction Washers enable a reaction-arm free tightening and simultaneous protection against self-loosening of bolted joints.
Special HEICO dual sockets enable compatibility with high-torque tools from most major manufacturers, allowing users to continue using their existing equipment, but now, reaction arms and external supports are no longer required. The reaction force is transferred directly through the gear-shaped outer geometry of the washer within the socket system, ensuring controlled load distribution. This allows the tightening torque to be applied purely axially, avoiding harmful bending moments.
For through-bolt applications where backup wrenches are traditionally required, HEICO has developed the HEICO-ONE Safety-Washer. This friction-based single washer features wave-shaped locking ribs on both sides, which immediately embed into the component surface and bolt head or nut, effectively preventing rotation of the passive side during tightening. This ensures a more accurate and much safer torque tightening process for through-bolt applications.
With significantly safer handling, reduced assembly times, and compatibility with major torque-tool systems, the HEICO-LOCK® Reaction Washers set new standards in advanced fastening technology.
HEICO Group - Quality. Innovation. Service.
With over 125 years of experience in fastening technology, the HEICO Group manufactures high-performance bolt locking solutions and pre-tensioning systems for tightening bolted joints.
“Quality made in Germany” has been the guiding principle of the company since its founding. Today, HEICO is recognized as an expert in the field of bolted-joint technology. From its production site in Germany, equipped with state-of-the-art production machinery, 430 employees serve more than 1.400 customers in 76 countries worldwide.
A high degree of vertical integration covering in-house tool and machine construction, in-house heat treatments and surface refinements, combined with continuous quality process controls has always defined the quality philosophy of the HEICO Group.
With 13 HEICO subsidiaries worldwide, supported by local warehousing and a strong national and international distribution network, HEICO ensures high product availability, short delivery routes, and professional technical support.
More about HEICO Group at:
