What Are Secondary Locking Devices?
Secondary Locking Devices are specialized hardware designed to assist in maintaining the integrity of threaded joints or assemblies under conditions where vibration, shock, or thermal cycling, are a factor. These loads are also known as dynamic loading as they are constantly changing.
Their primary function is to assist in preventing the loss of preload from occurring due to external forces acting upon the joint being fastened.
Some common types or features of Secondary Locking Devices:
Lock nuts (nylon insert, all-metal prevailing torque/deformed thread, etc.).
Spring washers (wave washers and tooth washers).
Wedge locking washers (two-piece washer systems using serrations & cam/wedge effects) These perform exceptionally well in applications involving high load high vibration.
Thread-locking adhesives or patch/thread coatings (e.g. anaerobic adhesives)
Inserts like helical coil inserts or elastomeric inserts which help maintain clamping in softer materials.
Proprietary locking fasteners are custom designed for specific applications, for which there are many.
Split-Lock Washers are commonly seen in applications for the purposes of resisting the impacts of vibration, however, Junker testing data shows these can actually increase the chances of rotational loosening due to reduced bearing surface friction.
How and Where They’re Used
Secondary Locking Devices are used wherever vibration, cyclic loading, or motion threatens joint integrity.
Benefits of Using Secondary Locking Devices
Using the right fasteners with Secondary Locking Devices properties delivers multiple benefits:
- Reliability & Safety: Reducing the risk of tension loss within the joint, lessens the chances of leaks, safety hazards, and fastener fatigue which could eventually lead to catastrophic joint failure.
- Lower Maintenance & Downtime: Fewer checks, re-torques, or part replacements. This saves labor and cost and avoids unplanned stoppages.
- Extended Service Life: Components and assemblies last longer since fasteners remain tight, avoiding fatigue or wear caused by joint slippage.
- Consistent Performance: Systems operate more predictably (e.g. less loss of preload, less noise, less dimensional shift over time).
- Total Cost Savings: Although Secondary Locking Devices may cost more upfront (or need extra features), they often pay off via savings in defects, recalls, maintenance hours, and material waste.
How Field Can Help
Field adds value beyond supplying parts. Here’s how Field can help customers integrate Secondary Locking Devices fastener solutions into their processes:
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Capability |
How It Helps with Secondary Locking Device Fastening |
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Value-Added Engineering |
Field’s engineers can review your joint designs and assembly processes to identify places where fasteners are loosening or failing, and recommend locking fasteners, special washers, thread-lock adhesives, etc. to improve joint integrity. |
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Vendor-Managed Inventory (VMI), Data-Driven |
Field’s VMI programs ensure the right fastener types (including Secondary Locking Devices variants) are stocked and available; minimizes overstock and stockouts. Ensures consistency in what is used, reducing variability that leads to failures. |
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Access to Many Suppliers & Products |
With over 900 global suppliers, Field can source special fastener types (lock nuts/washers, adhesive coatings, wedge washers, etc.) for demanding vibration-resistant applications. |
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Case Studies / Technical Line Reviews |
Field conducts audits and technical reviews of assembly lines to spot opportunities for improvement, including vibration-related loosening—and implement changes that yield measurable cost savings. |
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Quality & Standards |
As an ISO-9001 registered distributor, Field ensures traceability and consistency of fastener quality, important when using fasteners with critical locking or vibration-proofing features. |
Example Scenarios & ROI
- Imagine a railcar manufacturing line where bolts on signal light assemblies are loosening due to vibration. By redesigning the joint with the proper locking device and/or assembly strategy, you might reduce maintenance visits, reduce rejections, and overall labor cost—payback could occur in months.
- In HVAC or fluid management systems, vibration from pumps or flow turbulence can cause leak paths. Using Secondary Locking Devices, washers or adhesives prevents loose joints, reduces leakage, saves energy, or repair costs.
Final Thoughts
Secondary Locking Devices are not just “nice to have”—in many industrial settings they are essential for safety, reliability, and cost efficiency. But choosing the right fastener is not always obvious, and implementation touches design, engineering, supply chain, and maintenance. That’s where a partner like Field can make a real difference: combining technical expertise, supplier reach, inventory management, and engineering services to help customers not only choose good Secondary Locking Devices hardware but embed them in their process so that performance and savings are realized.