Trojan Special Fasteners Ltd routinely manufactures prevailing torque nuts to customer's requirements in multiple material and finish combinations.
Nylon insert nuts are a type of prevailing torque nut and are found here.
All metal prevailing torque nuts come in various different forms. These incorporate a locking feature that increases friction between the nut and it's mating part. This means that you have to apply a greater force to assemble the nut and also to remove it - ultimately this means that the nuts do not loosen with vibration. Additionally, these are all metal which means that they can be used in applications where excessive temperatures exist or where certain chemicals are used. Typically, they can be used up to 750 degrees C (or about 1400 Fahrenheit).
These type of nuts are typically reusable a number of times, but it has to be noted that subsequent removals reduce the 'prevailing torque' so they become less effective the more often they are removed and reapplied.
The greater the degree of deformation, the higher the amount of application and removal torque is required. The ISO 898 standard defines the amount of prevailing torque needed for metric fasteners and the IFI 100/107 standard defines the prevailing torque required for unified threads. No standard exists for the BSW and BSF threads.
It is recommended that these nuts are applied towards the ends of a mating part because the further they travel the higher the risk of damaging threads. Also, high strength all metal prevailing torque nuts must not be used low strength mating parts because the hard nut will act like a die and destroy the male threaded part.
Please note that Trojan Special Fasteners Ltd does not manufacture patented and trademarked items, but we have manufactured similar items based on customer drawings that utilise some of the prevailing torque locking mechanisms shown below; the following are only given as examples of all metal prevailing nut forms.
The types of all metal prevailing typically rely on deforming the nut in one way or another, the following forms exist: