What the heck is a Cage Nut?

Posted: May 16, 2012

Author: Robin Lieberman

What the heck is that?

Welcome to our “what the heck is that” series, where we discuss some of the unique fasteners and electronic hardware that manufacturers use in the design and assembly of their products. Today, we will introduce you to a fastener made of two pieces – this little guy is called the Cage Nut.

What the heck is a Cage Nut?

A Cage Nut contains a free floating threaded square Nut retained within a spring steel cage. The spring steel cage has two Mounting legs or wings that, when pressed together, allow the nut to clip into the square hole and lock the fastener in place within the rack hole.

Who uses Cage Nuts?

Cage Nuts are commonly used to mount lighting systems, electrical equipment or instruments onto rail racks. The Cage Nut clips into the rack’s square mounting hole and usually positions the Nut toward the inside of the rack. The Nut is typically loose or “floating” in the Cage to allow for adjustments when installing the screw. This configuration allows flexibility in mounting and assembling components.

AKA – Also know as…..

Cage Nut is a funny little guy and answers to a bunch of different names – some of Cage Nut’s favorite aliases are: Grip Nuts, Retainer Nuts, Rack Nuts or Floating Nuts. Lots of monikers!

Advantages of Cage Nuts

  • Snap directly into square rack holes
  • Easily installed with no special tools or skills, eliminating the need for special operations
  • The Nut floats within the spring-steel cage which offsets normal hole misalignment
  • Can be easily popped out and replaced
  • Ideal when removal or installation of rack components might cause holes to strip
  • Combines flexibility of spring steel cage with the strength of a threaded nut

Lessons learned- Considerations when selecting Cage Nuts

  • I always recommend purchasing the corresponding screw to go with the Cage Nuts (i.e. buy the 3/8-16 Cage Nuts together with the 3/8-16 screws). This prevents you from selecting the wrong size Cage Nut. To be 100% sure, you should do a quick test to make sure the screws and Cage Nuts fit together before beginning the installation process.
  • When it comes to installation, Cage Nuts can be tough on your fingers when trying to install or uninstall them with your bare hands. Consider using a Cage Nut Tool.
  • Sizing is based on 3 components: The screw thread, panel thickness and mounting hole. Double check your measurements before you make your purchase.

Cage Nuts in Stock at MF Supply

Here at MF Supply, we stock some of the most common Cage Nuts, including:

  • From imperial size 6-32 up to ½-13
  • Metric M5 and M6
  • Stainless Steel
  • Steel zinc plated
  • Tinnerman alternatives

And if you don’t see it listed, as always, ask us. Finding the right screw for you is our tag line after all!

For more detailed information on Cage Nuts, visit us at http://www.mfsupply.com/SearchResults.asp?Cat=1851.

About MF Supply

For over 35 years, MF Supply has been a trusted supplier of Fasteners and Electronic Hardware to OEMs, machine shops, manufacturers, and assemblers of machines and instruments in New Jersey, the greater NYC Metropolitan area and beyond. We are wholesale only.

  • Phone: 888-972-7397 [888-9-SCREWS]
  • Email: sales@mfsupply.com
  • Online: www.mfsupply.com


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