Toplock Stover Nuts in Grade C Zinc Plated Steel
Prevailing Torque Cone Lock Nuts
Prevailing Torque Lock Nuts, commonly known as stover hex lock nuts or toplock nuts, is a type of distorted thread nut with distorted threading being on the nut's conical end. For this reason, they are considered one-way nuts as the nut can only be started on one end of the threading. It's also why they are called "toplock" or "top lock" nuts.
The nut's distorted threading gets stretched as the fastener is inserted into it, causing friction between the nut and fastener and creating the locking action. The elastic nature of the deformation of top lock stover nuts means they can be reused indefinitely. They are often preferred over nylon insert lock nuts because, being all-metal, they are not subject to the temperature and chemical limitations of nylon inserts.
Zinc Plated Steel
Zinc is by far the most common and economical type of plating for fasteners. The zinc plating adds a protective "sacrificial" top layer against corrosion while also adding a shiny finish to the fastener. Zinc plating is ideal for indoor use where it won't be constantly exposed to harsh elements.
Grade C steel is equal to Grade 8 and undergoes the same hardening process before the stover nuts are zinc plated.
What is a Stover nut?
Stover lock nuts are one-piece, all-metal prevailing torque hex nuts with a conical top and a flat bottom. They are a type of distorted thread nut with the distorted threads being at the top of the nut where it becomes conical. Stover is another name for conical locking nuts, along with Toplock nuts and prevailing torque nuts.
What is a top lock nut?
A top lock nut is a kind of distorted thread nut with the distortion being at the top of the nut, towards the conical section. Because the threads are distorted on one side, the nut can only be driven one way onto a fastener. The distorted thread creates friction between the nut and fastener, creating the locking effect.
Which nut is made with a deformed top thread?
A distorted thread locknut is a nut that uses deformed threading to keep nuts from loosening from vibration. The specific nut would be a top lock or stover nut for a deformed top thread, which are kinds of distorted thread locknuts.
How does a top lock nut work?
As a male fastener is threaded into a top lock nut, it stretches the nut's threads once it hits the distorted section. The distorted threads act with elastic nature, increasing the nut and fastener's friction and creating the locking action.
Can you reuse a Stover nut?
Yes, Stover lock nuts are reusable. Theoretically, the nut's distorted thread's elastic nature can allow the nut to be reused infinitely. In practice, the nut loses its elasticity slightly with each use. It can be reused multiple times, but it's generally recommended to use new Stover nuts after several re-fastenings of the nut and in critical locations.
What is a prevailing torque lock nut?
A prevailing torque nut is any type of lock nut that has a prevailing torque to assist in preventing self loosening. Technically speaking, nylon insert locknuts fall under this description. Still, if someone refers to prevailing torque lock nuts, they typically refer to Stover or top lock nuts.