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
    • 2551
    • 0.232
    • 2552
    • 0.296
    • 2553
    • 0.385

Ratings & Reviews

4mm Allen Nut Hot Rod Truss Rod

  • Based on 96 Reviews
Displaying 8 of 10 1 2 3 4 5 6 7 8 9 10
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Easy To Install

By Clell from Dallas, TX
(Customer's Reviews) Friday, May 13, 2011

Easy to install and adjust. Its the only rod I use in my custom necks now. They are a little deep so watch you neck thickness at the nut.

Spoke Wheel truss rods are great!

By Matt Phillips from West Hills, Ca
(Customer's Reviews) Friday, May 06, 2011

I recently started using StewMac's spoke version of the hotrod truss. I have to say these are awesome... I was not able to find these from anyone else. The construction is top notch (as always) and they add extra ease and simplicity to the setup.
Thanks StewMac...

The perfect truss rod for that special build!

By Eric C. from Las Vegas,Nv.
(Customer's Reviews) Thursday, May 05, 2011

This is the only truss rod i've ever used for all my builds and will always be the one I order. The double action is very handy for adjustments. Don't forget to order the special sized router bit for this truss rod here at Stew Mac!

Well done!

By Mitchell Henderson from NS, Canada
(Customer's Reviews) Tuesday, April 26, 2011

Just a great piece, will be using it in the future for sure!

To the person who said:
"If you hit the strings very hard, you can hear some truss-rod rattle from the neck. I can't figure out, how to eliminate this."

The best way to fix this(as stated by stewmac, i think) Is put a bit of silicon caulking in the channel(ONLY A LITTLE!) then press the truss rod in, and glue the fretboard. The Silicon will keep it from rattling, and won't bind it up, either.

get the job done...

By smashedguitars from San Antonio, TX
(Customer's Reviews) Thursday, March 24, 2011

I've used these on about 10 guitars over the years... they work fine for me, but to be honest I prefer a traditional rod. just feel it's less invasive... I make 3 piece necks and sometimes use carbon fiber rods, so Ive never run into an issue that needed a correction the other way...

4mm hex

By Chad83 from Western Australia
(Customer's Reviews) Monday, March 21, 2011

Works great! i use these in all my builds.



By gabriel.v.savoie from Montr+¬al
(Customer's Reviews) Friday, March 04, 2011

It probably is the simplest truss rod to use in any guitar, acoustic or electric. It works very well, simple to use and reliable.

No pain in the neck!

By Trident Guitars from Berkley, Michigan
(Customer's Reviews) Thursday, March 03, 2011

I use these truss rods in all my guitar necks. They are easy to install and they work great. My necks are meaty and these truss rods can adjust them easily.

Good quality trussrod

By Ricardo Fonseca from SP, Brazil
(Customer's Reviews) Monday, February 28, 2011

I recommend this trussrod, works very well as expected. The 14 1/4" size is also appropriate for short scale electric guitar too, specially Gibson-like set neck guitars. Use the 18" just for long-scale guitars (25 1/2").

Good truss rods

By B Patrick from Conway, AR
(Customer's Reviews) Wednesday, February 23, 2011

I installed these into two 000 guitars. Easy installation and they are working fine.

Displaying 8 of 10
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Shown on page 72 of our latest catalog.
  • Hot Rod® is a registered trademark of Stewart-MacDonald Manufacturing Company, Inc.