A locknut, also known as a lock nut, locking nut, self-locking nut, prevailing torque nut, stiff nut or elastic stop nut, is a nut that resists loosening under vibrations and torque.
How many times can you use a Nyloc nut?
Nylock nuts are the most common and inexpensive self-locking aircraft nuts. These elastic insert nuts are inexpensive and almost infinitely reusable. Nylock nut tensile strength is rated at 125,000 psi with a 250°F temperature rating.3 Apr 2007
How does a prevailing torque lock nut work?
The prevailing torque in prevailing torque locknuts comes from localized plastic deformation to an interference fit with continuous sliding during assembly. Continuous sliding - contacting thread surfaces of the locknut and bolt are sliding across each other as the nut is installed.3 Jun 2014
What is a prevailing torque bolt?
What is prevailing torque in fastening? Prevailing torque is defined as the driving torque required to overcome friction in a threaded fastening application, which produces no clamp load, or bolt stretch.10 Jun 2020
Are prevailing torque nuts reusable?
The prevailing torque locknuts can be reused only for a limited number of times because each time the nut is used, there is a decline in its prevailing torque quality. That is why it is recommended to use thread lubricants and torque valves.
What is prevailing torque feature?
By definition, "Prevailing-torque locking fasteners have a self-contained feature which creates frictional interference between the threads of the mating components." Consequently, unlike free spinning lock nuts, there is a resistance to rotation during both assembly and disassembly requiring them to be wrenched; that
What is the prevailing torque?
Prevailing torque is defined as the driving torque required to overcome friction in a threaded fastening application, which produces no clamp load, or bolt stretch.10 Jun 2020
How do you calculate prevailing torque?
The prevailing torque will vary less than 75% from the value shown from the first to the fifth installation and beyond. 3) Calculated using formula: Nominal diameter x Clamp Load (from note 1) x Friction factor (dimensionless value of 0.20 for dry installation).
Is prevailing torque the same as running torque?
The prevailing torque is the torque required to run a nut down a thread before engagement with the joint surface. A prevailing torque can significantly affect the amount of preload provided by the fastener for a given tightening torque.