A thread locker is an adhesive compound that locks threaded connections of nuts, bolts, and screws preventing movement caused by vibrations and shocks. It is widely used in manufacturing and construction because of its durability and high functionality. They are made from curing chemicals that form a strong film to fill the gaps between the thread connection for locking it. Threadlockers protect the bolts and fasteners from harsh vibrations, bending, and other environmental factors.

Mechanical solutions are also used for locking with the help of lock nuts, washers, or nylon inserts that are inexpensive and readily available but come with certain limitations. Read this article to find out which method is better and more durable, between thread lockers and traditional fastening methods.

Traditional Fastening Methods

Traditional mechanical solutions prevent the fastener from rotating or loosening caused by vibration using mechanical locking devices such as:

Tab Washers

These metal devices have multiple tabs and notches around them to lock the fastener. They need to be replaced because of bending issues.

Locking Washers

It’s a free-spinning device with radical teeth to form a strong grip below the bolt to keep it in place. They are liable to corrosion as they are not sealed and may damage the bearing surfaces.

Nylon Insert Nuts

These nuts are like torque devices that create extra thread friction. However, in high-vibration environments, they are not recommended.

Many of these mechanical solutions perform a decent job, but problems like being susceptible to loosening and corrosion may lead to machinery failure. On the other hand, thread lockers are durable and often outperform traditional fastening methods in the following ways.

Threadlocker and Traditional Fastening Methods: Which One is Better?

Threadlockers provide strong adhesion and overcome traditional mechanical fasteners' limitations.

1. Filling the Voids

No matter how small the gap is, the major issue will be the air gaps caused by the mechanical fastening devices. Because of these gaps, loosening occurs due to constant vibration, whereas thread lockers fill the gaps with thin film and remove the air between them. They provide a surface-to-surface seal and lock it tightly, reducing the freedom to move while in operation.

2. Prevent Corrosion

Due to various environmental factors such as weather or temperature, rusting occurs between bolts and other threaded assemblies, usually caused by moisture. Thread lockers are designed with chemicals to provide high resistance to corrosion and don’t get compromised by the presence of water or salt.

3. Multiple Applications

Threadlockers are applicable to a wide variety of threads and fittings, unlike traditional fasteners. They ensure whatever tool or machinery you use, fastening will be done effectively and quickly without compromising its quality.

Here are a few great examples from 3M:

TL22 is removable with hand tools.  It is a low strength (low torque removal) threadlocker for small diameter, fine threaded screws, set screws, nuts, bolts and hex and slot driven components such as keyed fasteners.

TL42 is a general purpose. Removable with hand tools, medium strength threadlocker ideal for machine tool access bolts, and hydraulic system bolts.  It can also be used on gear box / driveshaft bolts, bearing cover cap screws, countersunk screws, and conveyor roller bolts.

TL43 is a general purpose, removable with hand tools, medium strength threadlocker for most medium and coarse threaded screws, nuts and bolts.  It is oil tolerant to help secure as-received parts and its thixotropic property prevents run-off, dripping, or migration of the adhesive product when applied on parts.

TL62 is a medium to high strength threadlocker that is especially developed to secure assemblies with high strength retention.  It allows disassembly with heat and will perform on lightly oily parts with only approximately 10% strength reduction.

TL71 is a general purpose permanent high strength threadlocker that locks bolts and studs up to 1” in diameter as it seals against leakage and corrosion.  Temperature resistance intermittently up to 400oF.

TL90 is a low viscosity to provide a wicking action, medium strength threadlocker that locks and seals small compression and ferrule fittings with service temperature up to 400F.  It is useful for pre-assembled parts.

Conclusion