Nuts play an important role in many fastening assemblies. They are used in conjunction with a threaded fastener, such as a bolt, to hold two or more parts together. A threaded fastener is inserted through the parts, after which a nut is twisted onto the end of the fastener. Tightening the nut will create a clamping force that holds the parts together. Cone lock nuts, however, go one step further to ensure the fastened parts don’t loosen and separate from each other.
What Are Cone Lock Nuts?
Cone lock nuts are specialized nuts that are designed to resist loosening. They feature a similar hexagonal shape as standard nuts, allowing them to be easily installed and removed using a wrench or socket. The difference is that cone lock nuts have a tapered, cone-shaped section above the hexagonal section.
Loosening is often a concern when using fastening assemblies. If a standard nut comes loose — whether from vibrations or other external forces — it will no longer create a clamping force. The parts fastened with the bolt and nut may then separate from each other. Cone lock nuts are designed to prevent this from happening.
How Cone Lock Nuts Work
Unlike nylon-insert nuts, cone lock nuts don’t rely on a soft insert to resist loosening. Instead, they use an all-metal design with deformed threads. The threads around the tapered section are intentionally deformed, which allows cone lock nuts to grip threaded fasteners.
When you tighten a cone lock nut onto the end of a bolt, the deformed threads will press tightly against the bolt’s threads. The end result is friction or “prevailing torque.” You can still loosen cone lock nuts, but they require greater force than standard nuts due to this friction. The friction of the cone lock nut’s deformed threads pressing against the bolt’s threads helps to resist rotational forces.
Why Cone Lock Nuts Have a Tapered Section
You might be wondering why cone lock nuts have a tapered section. After all, cone lock nuts use deformed threads to resist loosening; they don’t use their tapered section.
Cone lock nuts have a tapered, cone-shaped section to identify their locking threads. The deformed threads, which are responsible for locking the nut onto the bolt, are located around the cone-shaped section.
Cone lock nuts essentially have a locking end and a bearing end. The locking end features the tapered section. The bearing end, on the other hand, features the hexagonal section. Therefore, you should always install cone lock nuts with the tapered section going onto the bolt first.