What Is a Jam Nut?

When it comes to varieties of nuts and bolts, it can be tough to remember the functions and uses for each.


A jam nut plays an invaluable role for moments when a standard nut just won't do the trick. .

A jam nut is a thin nut that jams against another locking it in place and preventing another nut from moving. It is most commonly used in situations where larger, more standard-sized nuts will not fit.


A jam nut comes in handy when you need to lock an item in place using a nut without the support of a second object. The jam nut is used as the "second object." A jam nut is also used to secure an item without applying any force to it.


Using a jam nut eliminates the need to introduce a second, unnecessary object simply for fastening purposes. Now, whatever you are trying to join together can be done simply by incorporating this one small nut.


Jam nuts are small, coming in at half the height of a standard nut. It measures in at 5/8 inches on average.


Contrary to common usage, the lock nut should be put on the inside of the nut you are trying to lock down.

About the Author

Lynda Moultry Belcher is a writer, editor and public relations professional. She worked for a daily newspaper for 10 years and has been a freelance writer for more than 15 years. She has contributed to Divorce360 and Revolution Health Group, among other publications. She is also the author of "101 Plus-Size Women's Clothing Tips" and writes "Style At Any Size," a bi-weekly newspaper column.