What is the difference between a hex nut and a jam nut?

Asked by: Tim Hawkey

Hex jam nuts are low profile – usually only about half as thick as a standard hex nut. Commonly used as a type of lock nut, the jam nut is “jammed” against a standard nut to lock the two in place. Jam nuts are also sometimes used in applications where a traditional, larger profile hex nut would not fit.

Is a jam nut the same as a hex nut?

Hex jam nuts are thinner than a standard hex nut but have the same dimension across the flats and corners. Hex jam nuts have two common applications. A jam nut can be threaded onto a bolt and run tight against the standard nut which will lock the nut in place and prevent it from backing off.

What is the purpose of a jam nut?

Jam Nuts. Jam nuts, or half nuts, are a low‑profile hex nut with a profile half the height of a standard hex nut. Jam nuts are used as a locknut to prevent vibration from loosening a bolted joint.

What is the difference between a jam nut and a lock nut?

Also called a half lock nut, a jam nut has a lower profile than standard nuts and designed to be tightened – or jammed – against another nut. The jam nut by itself is not a lock nut – it’s the function it performs that earns its place here.

Can you use a regular nut as a jam nut?

The term “jam nut” can also refer to any nut that is used in the same function (even a standard nut used for the jamming purpose). Jam nuts, other types of locknuts, lock washers, and thread-locking fluid are ways to prevent vibration from loosening a bolted joint.

Do I need a jam nut?

Small (jam nuts) are frequently used since there is no need to have a full height nut on the bottom since the threads do not carry the load. An advantage of a thin nut in this application is that a greater amount of axial backlash will be provided for a given tolerance class.

How do you remove a jam nut?

Use a 6-sided wrench or socket. If the bolt still won't break free consider using a tool extender to added torque just be careful not to break off the head of the bolt.

Do you torque a jam nut?

The jam nut is a thin nut, normally used under a full nut to develop locking action. Recommended practice is to torque the jam nut to seat only, then assemble a full nut on top of the jam nut and torque to full preload value while the jam nut is held stationary.

How tight does a jam nut need to be?

And i know that's pretty ambiguous. But i think you can feel it as you start to tighten it you know you get contact a little bit of push. And that should be snug you.

Which way does a hex nut go on?

So if you look at the lock nut one side has a tapered crown to it and that's the side that goes up another way you can tell is if you look at one side of the lock nut it looks very round.

What does a hex bolt look like?

What does a hex head bolt look like a hex. Head bolt is characterized by a six agonal head shape. Which is flat on the top.