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

Easy to install and works great

By Robert S from Virgil, NY
(Customer's Reviews) Thursday, August 18, 2011

I've used these in several guitars and basses. They are far superior to the traditional Gibson style truss rod setup. For one, they install easy - just cut the flat channel, and pop it in. No top filler stick is required. No cutting, tapping of threads or peening and anchor nut. They adjust upbow and backbow, and respond quickly to just a slight turn of the nut. Well worth the few extra dollars. They are a bit deep, so pay close attention when shaping your neck in the erea below the nut.

Pretty straight forward

By MM from Australia
(Customer's Reviews) Wednesday, August 03, 2011

Nice sturdy rod and very easy to install. The only minor scruple I have is that the adjustment nut gained a bit of surface rust fairly quickly. Other than that it is a great product, happy to have used it

Easy to install

By JZ Guitars from Edison, NJ
(Customer's Reviews) Saturday, July 30, 2011

These are not only high quality but much easier to install than conventional truss rods. And they adjust both ways, can't ask for a better product.

4mm Allen Nut Hot Rod

By DiLorenzo from los osos ca.
(Customer's Reviews) Friday, July 15, 2011

I couldn't be more pleased. The installation of the truss rod & carbon fiber rods was as simple as it could possibly be when used with the corresponding router bits. I will be able to show my customers my commitment to high quality in the instruments I build by the use of these products provided by Stew-Mac. Thanks, I haven't been disappointed with any product I've purchased from Stew-Mac yet. Thanks, "Doc" DiLorenzo guitars & basses

Good truss rod

By Alan Campion from France
(Customer's Reviews) Wednesday, July 13, 2011

I installed this Hot Rod truss rod in my guitar neck and it fits correctly, thanks for the instruction note delivered with it

I love this rod

By Goodson Guitars from Odessa, Tx
(Customer's Reviews) Sunday, July 10, 2011

I use this rod in all of my guitars and if I rebuild a neck this is the rod I use.


By Cristiano Bochese from Verona, Italy
(Customer's Reviews) Sunday, May 29, 2011

I installed this truss rod in a strat style guitar. Easy to fit and it works very well!!!

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

Shown on page 72 of our latest catalog.
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