4mm Allen Nut Hot Rod Truss Rod

  • 96 Reviews
  • Write a review

A smaller 4mm (5/32") Allen nut for most instruments. Smooth two-way action corrects upbow and backbow, giving complete control over the neck.

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12-1/4" overall length

Item # 2550
In stock, ready to ship!


6 or more $13.74
12 or more $12.95

14-1/4" overall length

Item # 2551
In stock, ready to ship!


6 or more $13.91
12 or more $13.11

18" overall length

Item # 2552
In stock, ready to ship!


6 or more $14.78
12 or more $13.93

24" overall length

Item # 2553
In stock, ready to ship!


6 or more $18.26
12 or more $17.21
Quantity Discount Prices apply when you buy multiples of the same item number.
Total: $0.00
Quantity: 20


A smaller 4mm (5/32") Allen nut for most instruments. Smooth two-way action corrects upbow and backbow, giving complete control over the neck.

Easy to install. The Hot Rod® fits in a straight channel. For proper operation, this truss rod must be installed so that the active rod (the rod with the adjustment nut) is below the passive rod. A wooden filler stick is not required.

Smooth 2-way action with superior strength for stubborn necks.
Our Hot Rod neck adjustment system features twin rods in threaded brass collars. The stainless steel active rod turns for smooth neck alignment, with 2-way action to correct upbow and backbow.

The Hot Rod requires an access cavity for the adjustment nut, and a straight 7/32"-wide x 7/16"-deep slot (measured from the bottom of the fretboard) for installation.

Pick the Hot Rod Truss Rod size you'll need:
(overall length includes the nut)

Resonator guitar
Acoustic guitar with 12th fret at the body
Acoustic guitar with 14th fret at the body
Electric guitar

We've designed the Router Bit for Hot Rod Truss Rods especially for routing your neck to fit our truss rods.

Product Instructions

Hot Rod Adjustable Truss Rods

Installation and adjustment instructions for Hot Rod Adjustable Truss Rod.

    • Item #
    • Weight
    • 2550
    • 0.197 lbs. (0.09 kg)
    • 2551
    • 0.232 lbs. (0.11 kg)
    • 2552
    • 0.296 lbs. (0.13 kg)
    • 2553
    • 0.385 lbs. (0.17 kg)

Ratings & Reviews

4mm Allen Nut Hot Rod Truss Rod

  • Based on 96 Reviews
Displaying 3 of 10 1 2 3 4 5 6 7 8 9 10
Write a review

Hot Rod

By Bill Konings from Hamilton ,New Zealand
(Customer's Reviews) Monday, July 08, 2013

Being new at this game I had to work out how it all worked. Google again is a great help. and the instruction that came with it helped too.

Nice quality but check your measurements

Saturday, June 22, 2013

These are really well made. I like the red shielding on the rods and the dual action makes them work really well on finicky necks that need a replacement rod. The only problem with the rods isnt their performance. Its their size. If you are making a thin neck profile, they may not work. They are quite tall. I do like the nice squared off brass nuts. With the router bit that's made for these, the rods fit nice and snug. Don't forget a little silicone caulk at the ends. I also would recommend adding a drop of oil on the threading of each rod where it threads into the nut. then work it in and out a few times. Once its sealed in the neck it will help the brass from bending or binding. Brass is pretty soft but if its lubed up it works like a snap.

Smooth and solid

By Johnny Banjo from Michigan
(Customer's Reviews) Sunday, May 12, 2013

This truss rod worked great for my banjo build. I would surely use it again!


By Dave Jazzphantom
(Customer's Reviews) Tuesday, March 26, 2013

Was a bit hesitant about cutting the truss rod channel - but worth it: Truss rod works like a dream - Very tough little "Dude"

Hot Rod Truss Rods

By Tom Palecki from Cornville, AZ
(Customer's Reviews) Thursday, February 28, 2013

I use these in every guitar I build and wouldn't go back to single rods at all. For me they are easy to install and work great. Thanks StewMac. Tom at AZGuitars.

2 way truss rod

By Hans-J++rgen Jul from Frederiksberg Denmark
(Customer's Reviews) Saturday, February 23, 2013

I used them once, and I`m never going to use anything else. They are effortless too, and provide tremendous control over the neck. By using two carbon fiber reinforcements on either side of the truss rod, it is possible to make a very thin but very strong/stiff neck.

Hot Rod Bass Truss Rod

By TimCompton from UNIONVILLE, TN
(Customer's Reviews) Thursday, February 21, 2013

This was my first time replacing a Truss Rod on any instrument, but the instructions were detailed, and the product performed flawlessly!! Really great Truss Rod! I did research the fretboard removal using a clothes iron and wet cotton sock, worked very well. Thanks Stewart- MacDonald!!!

Dual Action Truss Rod

By Adam Bloch from Buffalo, NY
(Customer's Reviews) Thursday, February 07, 2013

I love these rods. They go in all my builds these days, along with a pair of carbon fiber reinforcement strips. My necks are absolutely rock solid and stable, yet still still have just enough give in them to perform neck bends when desired. That can be a tough balancing act for any luthier to achieve, but these rods make it easy.

Also, the perfectly sized router bit that Stew Mac sells for both the rods and the carbon fiber strips makes installation a breeze.

Dual action truss rod

By Nick Teasley from Marietta, GA
(Customer's Reviews) Saturday, February 02, 2013

These are a great item. I have only used these truss rods in my builds, and they perform flawlessly. Easy to install, and adjust; they simply just work!

Dual Action- Gotta love it

By Adrian Stuckey from Gold Coast Australia
(Customer's Reviews) Sunday, January 27, 2013

Easy to install and peace of mind

Displaying 3 of 10
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Shown on page 72 of our latest catalog.
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