Reduce unplanned downtime

Optimise assemblies and reduce unplanned downtime with LocTite.

MECHANICS OF A THREADED FASTENER AND FACTORS THAT AFFECT IT’S RELIABILITY

Tightening the nut on a bolt stretches the bolt, much like a spring. In technical terms, you elongate it. Elongation is necessary for creating the clamp load. More torque results in more elongation and, in turn produces more clamp load.

The clamp load keeps the two components together, creating friction in three ways:

• Between the bolt head and the clamped components

• Between the nut and the component / flange face

• Between the threads of the nut and the bolt.

You should think that all this together should be enough to keep the bolt tightened and hold the pieces together no matter what, but not really.

There are certain cases where threaded fasteners keep static assemblies together. In those cases, they’ll hold just fine. However, they are also used on many assemblies that are subjected to load and vibration.

Vibration will cause side-to-side movement of the nut and bolt because the threads don’t fit tightly enough to entirely fill the space between them (no matter how tightly pressed together they seem to the naked eye). Mechanical fasteners like a washer can be added, but this still does not resolve the issue of the spaces between the threads of the nut and bolt. Once vibrational stress becomes greater than friction, the bolt will loosen. It usually takes 50-100 cycles for the threaded assembly to completely fail.

Apart from vibration, there are several factors that can affect the reliability of a threaded assembly. For example, relaxation in bolt tension can occur due to settling of the nut head and creeping of the gasket. In case of different substrates being joined, variable service temperatures can cause different thermal expansion of the materials, which will also negatively affect the fastener performance. Finally, good old corrosion, a well-known enemy of metal assemblies, will inevitably occur due to humidity and elevated temperatures. We all know that corrosion is not good, whether it’s from the perspective of affecting the functionality of the assembly or making a disassembly more difficult (seized bolts and nuts) when repair ormaintenance is required.

A lot of these issues can be eliminated bysimply making sure that the gaps betweenthe threads are completely filled – and liquidthreadlockers are a solution that has beenaround for almost 70 years now.

The benefits of using a LocTite threadlockerextends beyond just locking the bolt in place.It also prevents corrosion and galling, providesexcellent chemical and thermal resistance, as wellas making disassembly for maintenance easier.One LocTite threadlocker 50ml bottle replacesover 800 standard washers on most commonbolt sizes.

The red LocTite bottle itself is a bit of acelebrity in its own right. This year it will beundergoing a ’rejuvenation, making it easierfor the customers to recognise the originalLocTite red bottle.

• STOP FASTENER FAILURE BEFORE IT HAPPENS

• TIGHTEN YOUR OPERATION. ELIMINATE LOOSENING

• TRADITIONAL FASTENING METHODS HAVE GAPS. THREADLOCKERS FILL THEM.

Should you wish to run a trial with LocTite, Call: 011-617-2400 | Email: za.agmarketing@henkel.com