What Is an Internally Threaded Jack Nut (Molly Nut)?

If you are looking for an inexpensive internally threaded fastener to quickly join a parent material with a secondary attachment (join two materials together), then look no further than the Jack Nut fastener! Rivet Nut USA, a division of Cardinal Components, has them in stock every day for just-in-time delivery into your production line.

Warning! Jack Nut fasteners are tough to find, many manufacturers don’t stock Jack Nuts, instead they are treated as a special made-to-order specialty fastener with a 26+ week leadtime. But, you are in good hands as here at Rivet Nut USA (a division of Cardinal Components, Inc.), as we have Jack Nuts in-stock or just a week away, due to the good obtainability within our supply chain.

Jack Nut Fastener (Molly Nut)

Pictured: A zinc plated 1/4-20 Jack Nut (grey/silver colored) installed into a 0.180 inch thick washer (black colored)

The benefits of a Jack Nut fastener are no damage or warpage to soft plastics or thin sheet metals, fast to install, economical to purchase and easy to use!

A Jack Nut fastens quickly and securely into a parent application, without needing access to the backside of the parent application. A secondary attachment then can be affixed to the parent application, by threading a bolt through the secondary attachment into the Jack Nut. The Jack Nut sometimes can be considered a “lighter duty” version of a Bollhoff PLUSNUT®, the Jack Nut is less expensive and offers less threads, and (much) less performance than a PLUSNUT®.

Mounting Parent Materials Include: thin, soft or brittle materials, such as thin sheet metal, soft plastics, wood, ceramic, delicate glass, etc.). When tightened, the Jack Nut body upsets and collapses to form four points that grip the backside/inside of the mounting parent surface, leaving a reusable threaded insert on the frontside.

Installation:  Jack Nuts can be installed extremely easily due to the four large slots cut into the Jack Nut body. At low volumes, they can be installed with a nut, bolt and two wrenches, most of which are probably already in your toolbox. At medium or higher volumes, a manual or pneumatic tool could do the trick.

Material and Plating:  Jack Nuts are available in steel (zinc plating) or brass material.  Sometimes, we add special coatings to further improve corrosion resistance, or add a special PVC, color, or rubber coating to prevent scratching soft parent material. Jack Nuts are RoHS and REACH compliant unless a non-RoHS or non-REACH material or plating is specifically requested by the customer.

Additional benefits:  When comparing a Jack Nut to a rivet nut or a PLUSNUT®, Jack Nuts:

• are less picky (less sensitive) to the hole size. For example, an oversized hole could work out fine with a Jack Nut.
• offer a very wide grip range, to grip thin and thick materials, which helps consolidate the amount of SKUs that a company may need to stock.
• extremely easy to remove, use a smaller driller bit and simply drill the Jack Nut out, it will likely come out in two pieces and a brand new Jack Nut can be reinstalled in the same hole.

Background

POP® was famous for its innovative designs and high-quality rivets and fasteners, which led them to create the Jack Nut. The ability to set various rivets and nuts without access to the back of the application made POP® products essential for a wide variety of industries and applications.

Through a series of acquisitions (Pop United Shoe Machinery Company (USM), Emhart Corp, Black & Decker), Pop eventually has now been folded into the product portfolio offered by Stanley Engineered Fastening Company.

Marson (now owned by Howmet Aerospace Inc.) offers their take on this product, the MQN series. Jack Nuts have also been called quad nuts, molly nuts, molly inserts, etc. Across the internet, you may see part numbers that begin with the JN series (Jack Nut), MQN series (Molly Nut) or JK series.

You may have trouble in sourcing this type of product, finding a seller of Jack Nut fasteners can be difficult, let alone finding a seller that has access to immediate stock. With that said, you are in good hands at Rivet Nut USA, just email us a part number, specifications or a photo, and we find the exact brand or a “functional equivalent” that is readily available.

Where are Jack Nut Fasteners Used?

Jack Nut applications can be used in a wide range of industries. The most common areas include automotive, aerospace, agriculture, electronics, manufacturing, and recreational vehicles. They are typically used in applications that don’t require great engineering performance, such as holding on a dated inspection plate that gets taken on and off every year, a stationary electrical enclosure or in a utility drawer. Jack Nut fasteners work exceptionally well in applications with extremely thin materials, upsetting in materials as thin as a piece of paper! Jack Nuts are made via battle-tested manufacturing processes that create long-lasting quality so you can be certain that a Jack Nut will perform well in the right fastening solution for your non-load bearing application.

Assembly Applications:

• Aerospace
• Automotive
• Agriculture
• Recreational Vehicles
• Electronic Components
• Manufacturing (dishwashers, refrigerators, any sort of thin metal or enclosure, etc.)

Specifications

Thread Sizes:

• Unified: 6-32, 8/32, 10-24 & 1-4/20 (Others available via special request)
• Metric: M4, M5, M6 & M8 (Others available via special request)

Product Dimensions:

See our webpage on Jack Nuts | Molly Nuts

Materials:

• Brass
• Steel with zinc RoHS plating

For 40+ years, Rivet Nut USA has been your comprehensive resource that provides high quality components which improves the quality of your product, extends the life of your application and are competitively priced. No matter what you’re looking for, Rivet Nut USA is your one-stop-shop for all your Jack Nut needs. We are the preferred distributor of fasteners and rivet nuts. Rivet Nut USA, has direct suppliers of Jack Nuts and we stock them for just-in-time delivery into a customer’s production line.

Need more assistance? Call Rivet Nut USA at 800.236.3200 or Contact Us to Request a FREE Quote or more information!