Cross Nut

Crossnut-Heading-1920-px

Cross Nut

Using cross nuts is a smart way to attach structural stuff to your van’s walls and ceiling: It prevents rust in the long term and it provides very strong anchor points for structural stuff (such as cabinets). Sounds promising, doesn’t it? Keep reading to learn how to choose the correct cross nut size and how to install them!

Disclosure: This post contains affiliate links, which means that if you click a product link and buy anything from the merchant (Amazon, eBay, etc.) we will receive a commission fee. The price you pay remains the same, affiliate link or not.

Portrait

1- Using Sheet Metal Screws

Screwing stuff directly into the van is fast & easy, so why even bother using cross nut in the first place? Like everything in life, the fast & easy solution often isn’t the best solution… Here are the potential problems by using sheet metal screws:

RUST

Look carefully: there is no unpainted surfaces in a van. Paint has a much bigger role than just being pretty: it protects the metal from rust. The action of screwing, drilling a hole or cutting metal removes the paint and the bare edge now becomes a potential ignition point for rust that will eventually propagate.

More Rust

The action of drilling or cutting metal will inevitably spread tiny metal chips around the work area; it’s possible to try to catch them, but not to a certain extend. Each metal chip that’s left on a surface is a potential ignition point for rust on that surface.

Electronics Interference

Modern vans are a bit finicky… make sure to follow the no-drill zones of your van. Such guidelines are normally provided by the manufacturer:

Weak Strength

Sheet metal thickness is around 0.032″ in a van… that doesn’t provide much grip for screws (not many threads are engaged in the metal). You’ll need a lot of screws to provide enough strength against vibration or accident.

2- Cross Nut Benefits

A Cross Nut is an insert that is installed into an non-threaded hole; it can be an existing hole (factory) or a new hole (drilled). Once installed, it is then possible to insert a bolt into the Cross Nut. Note that the Cross Nut is installed permanently into the van, but the bolt can be removed and re-installed.

Before Installation:

PlusNut, Pre-Bulbed

After Installation:

Crossnut no Crossnut

Here is what's going on:

cross-nut-simulation

Cross Nut Benefits:

Prevent Rust

Cross Nuts can be installed in existing holes (from factory); that means there is no need to drill new holes (and therefore exposing bare metal) for most of the conversion.

High Strength

A Cross Nut has an impressive pullout strength: 1215lbs (for 0.030″ thick steel) VS < 100lbs for a sheet metal screw…

Wide Grip Range

The same Cross Nut can be installed in a wide range of material thickness. For example, the 1/4-20 Cross Nut can be installed in metal thickness ranging from 0.020″ up to 0.280″.

Blind Installation

Cross Nuts can be installed even if you don’t have access to the other side of the panel (as opposed to a bolt, where you need to hold the nut on the other side).

Material

Cross Nuts can be installed in metal, but also in softer materials like wood or plastic.

3- Choosing Cross Nut Size

3.1- DIY

To choose the correct Cross Nut, there are 3 variables to account for:

Hole Diameter

This is the diameter of the hole receiving the cross nut. In other words: the diameter of the hole in the van. The most accurate way to measure a hole diameter is by using a digital caliper:

Grip

This is the material thickness of the hole receiving the cross nut. Again, a digital caliper is the most accurate way to measure this.

Thread

This is the diameter & pitch of the bolt you plan on inserting into the cross nut. For example, a 1/4-20 bolt means 1/4" diameter and 20 threads per inch (TPI). The thread of the cross nut has to match the thread of the bolt.

Cross Nut Buy Links

crossnut
HOLE DIAMETERGRIP
THREADBUY LINK
minmaxminmax  
0.312″0.317″0.020″0.175″10-32Amazon
0.386″0.391″0.020″0.280″1/4-20Amazon
0.484″0.489″0.020″0.280″5/16-18Amazon
0.562″0.569″0.020″0.280″3/8-16Amazon

3.2- Cross Nut for the Ford Transit

Ford Transit Medium Roof Medium Length White Iso
HOLE DIAMETER GRIP THREAD BUY LINK
min max min max
0.386″ 0.391″ 0.020″ 0.280″ 1/4-20 Amazon
0.484″ 0.489″ 0.020″ 0.280″ 5/16-18 Amazon
*BOLD = MORE COMMON.

3.3- Cross Nut for the Sprinter

Mercedes Sprinter Van
HOLE DIAMETER GRIP THREAD BUY LINK
min max min max
0.312″ 0.317″ 0.020″ 0.175″ 10-32 Amazon
0.386″ 0.391″ 0.020″ 0.280″ 1/4-20 Amazon
0.484″ 0.489 0.020″ 0.280″ 5/16-18 Amazon
*BOLD = MORE COMMON.

3.4- Cross Nut for the ProMaster

Ram Promaster
HOLE DIAMETERGRIPTHREADBUY LINK
minmaxminmax  
0.312″0.317″0.020″0.175″10-32Amazon
0.484″0.489″0.020″0.280″5/16-18Amazon

4- How To Intall Cross Nut

4.1- Using A Cross Nut Tool

This will save you time and trouble. Trust us, we installed all our cross nuts without tool and we wish we invested in the proper tool…

Astro 1450 Cross Nut Tool

4.2- DIY Installation

After installing 80+ Cross Nuts the DIY way, we wish we bought the tool above… we probably spent as mush in bolts & K-Nuts than the cost of the tool itself! Unless you’re almost done with your conversion, make yourself a favor and get the tool! But here’s how you can do it anyway…

Tools required:

  1. Carriage bolt (same type as your Cross Nut. 1/4-20 Cross Nut = 1/4-20 bolt. Buy from Amazon)
  2. K-Nut (it’s a nut with an attached, free spinning washer. Buy from Amazon). We found this type of nut will last MUCH longer than a regular nut (a regular nut will last for 1-2 uses only as opposed to 10-15 uses for the K-Nut)
  3. Box Wrench (or any drilled plate would do. This is just to prevent the Cross Nut from rotating when upsetting)
  4. Vise Grip (Buy from Amazon)
  5. Wrench (for turning the K-Nut)

1- Find a hole...

plusnut-demo-step-1

2- Insert the Cross Nut in the hole

plusnut-demo-step-2

3- Insert the box wrench, k-nut, carriage bolt and secure the vise-grip to the carriage bolt.

stackup

4- Upset

plusnut-upset

5- Remove the box wrench, k-nut and carriage bolt. That’s it!

plusnut-front-view

6- Bolt stuff into the cross nut!

plusnut-example

5- Installation Tips

5.1- How To Transfer A Holes Pattern

Now imagine you have to install a cabinet using 4 cross nuts. You install the 4 cross nuts into the van first and that creates a “pattern”. You must replicate this pattern into your cabinet, so the holes into the cabinet align perfectly with the cross nut locations. Here is what we did:

1- We got a bunch of hanger bolts:

Hanger Bolts

The hanger bolts you buy must be the same thread as your cross nut!

2- We installed a hanger bolt in each cross nut, sharp end pointing out:

3- Then we pressed the cabinet’s panel against the hanger bolts sharp end (all of them at once). This transfers the cross nuts pattern from the van’s wall onto the cabinet.

4- We removed the cabinet and drilled a hole at each cross nut location.

5- We put the cabinet back in place and bolted it through the holes we previously drilled into the cross nuts. Voilà!

6- On Second Thought...

Installing cross nuts is definitely more time consuming and complicated than screwing directly through the metal, but unless you’re converting an old rusty van, it will protect your investment in the long run AND it is stronger and safer. There is nothing like having the feeling you accomplished things the right way! 🙂

STAY IN TOUCH!

Join 30,000+ followers via Facebook, Instagram, YouTube, Pinterest, e-mail or Patreon:

about us

Nice To Meet You.

Hello! We’re Isabelle and Antoine 🙂 In 2017 we sold our house (and everything in it), quit our engineering careers and moved into our self built campervan. We’ve been on the road since then and every day is an opportunity for a new adventure; we’re chasing our dreams and hopefully it inspires others to do the same!

95 thoughts on “Cross Nut”

  1. Is it necessary to go with stainless 1/4×20 bolts? I already have the astro tool and plusnuts. I’m having difficulties finding bulk quantities of stainless 1/4×20 bolts in 1 3/4 or 2″ length

    Reply
  2. Hi there! Long time (2 months) reader, first time poster. Do you have a sense on how many cross nuts you used in your build? I’m just trying to get a sense on how many to order. We are getting the van in 2 weeks, but we are trying to get materials procured in advance to hit the ground running. We have insulation, fan, and wood squared away. My main concern is that the cross nuts are a bottle neck is not ordered now. Thanks in advance!

    Reply
  3. Bonjour Antoine
    Cet été, j’ai redécouvert le plaisir du camping en louant un dodge caravan et en y ajoutant des modules que j’ai fabriqué. Quel plaisir. Du confort et de la mobilité.
    A mon retour de vacance, je partage ma découverte à mes anciens voisins Marika et Mario… en leur faisant part de mon désir de poursuivre l’expérience avec un petit camion de type Promaster ou sprinter. Ils me parlent de votre expérience et votre site de partage. Je suis franchement ébahi. Moi même ingénieur, je m’y retrouve tellement. Vous êtes devenu ma lecture de chevet.
    Quelle belle aventure vous poursuivez.

    Reply
  4. The large plus nut .485 to .489 that you have linked for the ProMaster has a very limited use with only a handful of opening at that size. Most of the large holes are hex opening that are a bit too small for the round plus nut.

    I’m happy to use your Amazon links so you all get some $ for all the hard work. Any chance you’ll update that list with some hex rivets?

    Reply
    • I’d be happy to add Hex Nut to the list… Do you have exact dimensions of the hex openings for the ProMaster by any chance? Unfortunately we don’t have access to a ProMaster so it’s hard for us to advise 🙁 Thanks for your help!

      Reply
    • I used a hammer to get the 5/16 plusnuts into the hex openings. Some of them did bend the area around it a little, but it’s definitely worth having them in there.

      Reply
  5. Bonjour Isabelle et Antoine,

    Il est mentionné que les crossnut pour le Transit sont de 0.386 à 0.391 alors que lorsque je mesure les trous dans mon Transit 2019, j’arrive à 0.362. Est-ce qu’il y a quelque chose qui m’échapperait par hasard?

    Merci pour votre site, une incroyable mine d’information!!
    Caro&François

    Reply

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.