4mm Allen Nut Hot Rod Truss Rod

  • 93 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 93 Reviews
Displaying 4 of 10 1 2 3 4 5 6 7 8 9 10
Write a review

Great choice

By Mark Davis from Canada
(Customer's Reviews) Thursday, October 04, 2012

i am working to build a 7 strings LesPaul shaped guitar,For the Truss rod,I stopped my choice on 4mm which corresponded to my expectations, the build quality is excellent and the rod is adjusted to perfection, thanks StewMac.Mark Davis

True to its own design.

By Pharnton Smith from Douglas, WY
(Customer's Reviews) Saturday, September 29, 2012

This is not my first choice for truss rods. It's very deep, taking away more wood than neccessary, and the use of soft brass makes me nervous. Also because of the round top profile there is very little metal in contact with the fretboard. Still, it is a good execution of a design that does make a lot of sense.

truss rod

By bluesplayerx from ca
(Customer's Reviews) Thursday, September 13, 2012

well built and works fine

Hot rod

By Dean W Richardson from Kirkland, Washington
(Customer's Reviews) Sunday, September 09, 2012

Had never used this type before, was impressed with how well it works.

very nice truss rod

By mike ryman from erwin tn
(Customer's Reviews) Friday, August 17, 2012

I bought this double action truss rod for my first guitar build. I was very scared of installing a truss rod in general because of the whole cutting a deep slot in the neck and sanding through idea. It just terrified me. I wanted to make sure the rod could help adjust for a bow in either direction an i had never built a guitar. I was extremely pleased as well as surprised with the quality of the rod, and the ease in which it went in. I bought the special router bit made for the install and it went perfectly. Thank you stewmac!

so far so good

By JDCguitars from Hawaii
(Customer's Reviews) Wednesday, June 20, 2012

I bought this hotrod for the sole purpose of flipping it upside down and making it a headstock adjust on Strat and Tele style necks. so far so good

Wow this thing adjust amazing!

By Pestvic from Sparks NV
(Customer's Reviews) Tuesday, June 19, 2012

Take your time and make sure thing thing gets installed nice and snug and tight. Don't install this loose or it will rattle. I like to put some silicone or hot glue right before I install it so that it snugs itself in and doesn't rattle. I make sure mine fits perfectly, when you get it in just right the smallest little adjustments will change the neck big time. No more half turns or full turns to set the neck. Small quarter or less turns will make the adjustment you need. I will always use these truss rods in my builds.

Nice rod

By paul from dannemora
(Customer's Reviews) Thursday, June 14, 2012

These rods work very good stewmac also ships fast!!

Double stability for your guitar neck

By CJ Beuhler from Saskatchewan, Canada
(Customer's Reviews) Monday, May 21, 2012

I've used this rod in 3 scratch-built through-body necks now, and find that all three necks stay put once set-up. The only other guitar I've seen that holds relief this well is the Hagstrom, which uses a patented aluminum I-beam system.


By strateur from France
(Customer's Reviews) Wednesday, May 09, 2012

This product is very good but to be perfect it should be more small to make thiner neck.

Displaying 4 of 10
1 2 3 4 5 6 7 8 9 10

Shown on page 72 of our latest catalog.
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