AS9120B, ISO 9001:2015, and FAA AC 0056B ACCREDITED

What Is a Lockbolt

Lockbolts, as their name suggests, are bolts that lock in place when installed, preventing loosening over time, even under extreme stress and vibration. They find use in a wide range of applications where rivets or conventional bolts are often utilized as lockbolts display increased strength when compared to other options. To better understand lockbolts, this blog will outline their uses, types, and unique features.

A lockbolt consists of two components: a pin and a collar. They can be installed in the place of nuts, bolts, or rivets, with the added benefit that they do not require additional securing pieces like cotter pins or lock washers. Lockbolts can even be installed from one side of a workpiece, usually from the collar side. Meanwhile, the collar is pulled and swaged onto the lockbolt during installation, so that no torque is needed. Furthermore, lockbolts are available in two basic designs, those of which have separating pintails and those that lack separating pintails.

With and Without Separating Pintails

Lockbolts with separating pintails are designed with a breakpoint in the pin, allowing the tail to separate when installation is complete. The spent pintail is either ejected to the floor or collected alongside others in a container, if a containment system is provided. It is important to note that pintails have a narrower diameter to define the breakpoint, and some lockbolts may have multiple breakpoints to accommodate joints of varying thicknesses. Unlike a nut or a traditional bolt, the collar is set, swaged, and pulled onto the pin, so it does not move during installation. After the lockbolt has been set, the breakpoint removes the excess pin.

When installing lockbolts without separating pintails, keep in mind that the pin will remain after installation because there is no breakpoint. Depending on the application at hand, this type of lockbolt has two advantages. First, as there is no pintail, nothing needs to be collected after installation. Second, there is no loud noise when the pintail separates, reducing overall operational noise and operator fatigue.


Lockbolts are suitable options for manufacturing and construction applications where there are large amounts of vibration since they are not easily shaken loose. As such, many often describe them as being tougher than rivets or screw joints. The swaged locking collar is the key feature that provides lockbolts with their lasting strength and performance. Even precisely machined nuts and bolts will have clearances in the bolt thread that can make them loosen over time. However, the swaged collar creates a tight and permanent bond with the circular grooves of the bolt itself.

Another main reason lockbolts are preferred over other types of threaded fasteners is due to their ability to cut time, labor, and costs in terms of installation. By taking advantage of a lockbolt installation tool, you can apply pressure to swage the collar, drawing the pin in as part of the installation to achieve a tight joint. Upon setting the collar, the tool can remove the excess pin, and installation is complete.


Like other threaded fasteners, proper installation is critical to ensuring that your operations run smoothly. If, during installation, you require additional tools or replacement lockbolts, rely on a trusted distributor like Stacked NSN. Stacked NSN is a leading supplier of lockbolts and other fastening components, all of which have been sourced from top global manufacturers that we trust. With countless ready-to-purchase items, customers can meet even the most rigid time constraint with unmatched cost savings. Get started today by requesting a competitive quote on any featured item(s) and see how Stacked NSN can serve as your strategic sourcing partner. For additional inquiries, call or email us at any time; we are available around-the-clock!


June 25, 2024
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