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 6 of 10 1 2 3 4 5 6 7 8 9 10
Write a review

installing truss rods

By zex guitars from Serbia
(Customer's Reviews) Sunday, January 08, 2012

I am very pleased with the easy installation and quality truss rodss

short scale telecaster

By Nikos Taliadouros from Athens Greece
(Customer's Reviews) Friday, December 30, 2011

I have used your hot rod truss rods for more than ten constructions and repairs during the last two years. It works perfectly both in guitars and basses. Highly recommended. Greetings from Athens. Happy new year.

two way truss rods

By jungle guitars from goa india
(Customer's Reviews) Saturday, December 03, 2011

great quality but the depths of these rods are a little to deep be careful if your planning on a skinny neck would like to see these rods with a flat bar on the top rather than round to decrease the depth of the slot needed

Love these rods!

By Chris Thomas from Elizabeth, PA
(Customer's Reviews) Wednesday, November 23, 2011

I used to make my own 18" truss rods. I bought a couple of 6' stainless steel rods. I bought right and left handed taps and dies. I had my godfather make some anchors with right and left hand threads. They work great. But, it's a lot of work to cut your own threads and Dremel for the achors. Not to mention welding my own 1/4" hex adjusting nut.

These Stewmac rods are fantastic. Make sure you buy the router bit specifically designed to fit these rods. They go in soooo easily and the strength and evenness of the curve is great. I don't make truss rods any more. There's no need when they cost less than $16.

Works Very Well

By The Lefty Luthier from Spring Branch, Texas
(Customer's Reviews) Friday, October 07, 2011

A very powerful adjustment. Suggest full bedding with compliant silicon calk rather th.an just dabs at both ends as directed to minimize rattles.

one out of 2 ain't bad :$

By Adam P. from Tasmania, Australia
(Customer's Reviews) Monday, September 19, 2011

Just built my 2nd guitar using these truss rods, using a ball end allen wrench (as suggested on angle) has chewed the inside of the nut completely!! This metal in the nut must be really soft stuff, I barely got a 1/4 turn on my truss rod & an almost finished guitar is now screwed :(

Great Product

By TisDale Custom Guitars from Renton, WA, USA
(Customer's Reviews) Monday, September 05, 2011

I use the Hot Rod in all my custom guitars. It's strong, it can correct even the worst upbow/backbow with no signs of breaking. Very highly recommended.

Works great

By DanielK from California
(Customer's Reviews) Tuesday, August 30, 2011

Routing out the channel for this was easy. Adjusting the neck relief after the guitar was complete went well. The instructions are clear and get the job done.

4mm allen head hot rod

By Purplecarrot instruments from Michigan
(Customer's Reviews) Sunday, August 21, 2011

You'll likely need the special width router bit to get the exact slot width. I got close with two router passes of a 3/16" bit but it was a trick to set up. Got it installed and put the wrench in the socket just to loosen it up and the end broke off ! I'm quite disappointed and I can't return it now cuz it's stuck in the neck. Wary of trying this again, I prefer the old fashioned Gibson type for reliability.

Hot Rod

By Fuen from Coteau-du-Lac, Quebec, Canada
(Customer's Reviews) Thursday, August 18, 2011

This Hot Rod is perfect for my work! Can't wait to see the final result.

Displaying 6 of 10
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Shown on page 72 of our latest catalog.
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