S-RT® Free Running Thread Locking Nut From PEM

The self locking Self Clinching nut has been reinvented. Finally you can throw away those nuisance locking washers - for ever!

Thread locking nuts have been around for many years and generally offer very good results. However they have two significant drawbacks. First of all they are normally of the prevailing torque type which operate by putting a constant drag on the mating screw as it rotates to clamp the components together. This makes both starting the screw and then tightening it slower, more difficult and generally unsuited to power tools. Prevailing torque threads are also unsuited to setting with a predetermined torque setting or checking with a torque testing tool.

Secondly prevailing torque locking threads tend to become ineffective after a relativity limited number of cycles quickly making them unsuited to any application where repeated removal of the screw might be required such as in an access panel for instance.

S-RT® nuts from PEM use a completely different system to create a thread lock which means that the mating screw can be spun in entirely without resistance until a clamp load is applied. Once suitably tightened a vibration resistant joint is created without the use of additional locking washers or messy thread locking compounds. Even better the screw can be removed and the nut reused as often as required without any loss in thread locking performance.

Screws can be installed using powered screw drivers set to a suitable torque load to ensure that all mating screws are tightened to a consistent load.

PEM S-RT® nuts are physically the same dimensions as standard S-nuts and install into the same size holes using the same tooling. This means the change to thread locking nuts can be implemented seamlessly without any changes to components being required.

S-RT nuts are currently available in M3 to M6 metric thread sizes and unified sizes 4-40 to 5/16-18

For technical information go to our web page here or

Get In Touch With The Assembly Experts

If you’d like a sample or to discuss how to utilise PEM Self-locking nuts for your assembly requirements, get in touch with our friendly team of experts today on 0808 123 1221 or email sales@zygology.com.

You can also see more information on the new PEM S-RT self-locking clinch nuts available at Zygology here.

Zygology – The fastening experts for over 40 years!
We’re engineering product specialists that understand the practical applications of our fasteners & tools to provide you with bespoke solutions to your assembly requirements.

Our commitment to providing the best service & quality management is backed up by our ISO 9001 & UKAS Accreditations & we will always give the best advice we can - even if it means that we end up recommending a competing technology.

Combining friendly service & expert advice with competitive prices & excellent stock availability, our assembly solutions help you reduce your production costs & increase efficiency. Get in touch with our team today to discover how we can meet your assembly needs.