The locking of threaded fasteners has a significant bearing on the long term reliability of mechanisms across industry but when the application is under the bonnet of a vehicle, the efficiency of the thread locking method is particularly important. The prospect of a threaded fastener becoming loose on a car, truck or bus is concerning as it might cause damage to the vehicle and, potentially, prove dangerous. To overcome the limitations of conventional solutions, such as mechanical, friction and locking devices, more and more car repairers and restorers are turning to threadlocking adhesives. Indeed, this fact is confirmed by Henkel, owner of the LOCTITE® range, which has conducted a new survey in conjunction with a nationwide provider of both car parts and servicing/repairs.
Like all engineered assemblies, vehicle chassis structures and engines require ways of joining parts together, with threaded fasteners having long proven a favoured method of achieving the desired result. However, vehicles present special challenges as driving on the road produces vibration and dynamic loads, particularly when encountering hazards such as potholes.
To prevent the loosening of threaded fasteners, among the traditional solutions deployed are tab washers, nylon ring locking nuts, saw-tooth flanged bolts and wedge-type locking washers – but all have their limitations. Differential thermal expansion is a good example. Dissimilar metals have different thermal expansion coefficients, which may result in the loss of bolt tension and a reduction in clamping force. Another case in point is corrosion, where water ingress can lead to thread deterioration.
Aware of the need for a long-lasting solution, increasing numbers of those performing vehicle repairs and restorations are turning to material integration products, such as threadlocking adhesives, as confirmed by the new Henkel survey.
Scores of customers were asked about their experiences of using LOCTITE® 248 general purpose threadlocker, which comes in both liquid and stick form. Although the applications were wide ranging, the results were the same: highly successful.
Even for applications where safety was paramount, threadlocking adhesive provided the solution, as one respondent reported: “So simple and no mess – I needed this to lock the seatbelt bolts in place on a car I’m rebuilding.”
Excellent durability and controlled bolt tension are attributes of LOCTITE® 248 that ensure its suitability for almost all vehicle applications.
LOCTITE® 248, which is a single-part threadlocker, is purpose-designed to fill all voids and deliver vibration resistance. And word is clearly spreading, as the wide application range highlighted in the survey showed: “Bought as I was changing a cam belt and had to secure some bolts.” Another respondent stated: “I bought this to lock small screws on a water pump cover that used to rattle out.”
Motorcycles are also benefiting. One answer said: “Used on an accessory for a motorcycle to combat bolt slacking due to vibration. All good after many miles.”
In fact, the range of vehicle applications for threadlocking adhesives is clearly extensive, as another user outlined: “I used it for peace of mind in preventing caravan wheel bolts from loosening.”
All threaded fasteners have the same purpose: to ensure a durable assembly. However, the self-loosening of threaded fasteners is a leading cause of catastrophic failure in car engine, transmission and suspension components. By using LOCTITE® anaerobic threadlocking adhesives from Henkel, fasteners can be kept firmly in place. Although LOCTITE® 248 is medium strength, a choice of adhesive strengths are available to allow dismantling if required.
Anaerobic threadlockers cure in the absence of air when confined between close-fitting metal surfaces. The products are suitable for use on a wide variety of metal surfaces, including passive substrates such as stainless steel. Further benefits include a good tolerance to oil, and the prevention of corrosion and galling (as the threads are completely sealed).
For more information go to: www.henkel-adhesives.co.uk