4mm Allen Nut Hot Rod Truss Rod

  • 95 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 95 Reviews
Displaying 5 of 10 1 2 3 4 5 6 7 8 9 10
Write a review

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.

Hot Rods are The Best

By AZ Cigar Box Guitars Custom Shop from Chandler, AZ
(Customer's Reviews) Sunday, April 29, 2012

We make custom bass and six strings guitars in our custom shop and use the Hot Rod tension rods exclusively. Quality is excellent and they are very affordable. Another great product from Stewmac.

truss rod

By Richard Burns from Hoffman Estates Il.
(Customer's Reviews) Sunday, April 22, 2012

I am extremely satisfied with this purchase. While I thought it was reasonable priced,I have purchased one on internet for much cheaper, but it was no where near the quality of this still vary affordable one!

Very good double-action truss rod

By Gaca from Switzerland
(Customer's Reviews) Friday, April 06, 2012

I really like the idea of this truss rod, so I take one for test. ItÆs very easy to fit and it works very well for me û also for back bow correction.
Some possible improvements are already written in previous reviews: odd nut bright, even instead of round upper rod. I can recommend this item for standard application.

The Best!

By Ryan K from Calgary, Canada
(Customer's Reviews) Tuesday, March 20, 2012

This is the best style of the Hot Rod Truss rods. I won't use anything else and the 4mm Allen Nut style eliminates clearance issues one may have with a socket wall that is too thick to get between the space of the 1/4" nut and headstock veneer.

2way truss rod

By jjason from Cincinnati, oh
(Customer's Reviews) Thursday, March 08, 2012

It's a good truss rod setup. I needed to take an inch off the the long one I ordered so it took some messing around with it to get it apart and back together.

Excellent trussrod

By handson from Queensland
(Customer's Reviews) Monday, February 27, 2012

Just fitted the hotrod trussrod to my new neck very easy to route the slot and it fitted perfectly, adjusts easily,can't wait to finish the bass ,will be using these again ,thanks.

Best standard ones around

By Strandberg Guitarworks from Uppsala, Sweden
(Customer's Reviews) Thursday, January 26, 2012

I like these, just wish that they were lighter. Also, some lubrication of the threads would not hurt.

Good Truss Rod

By Ben Fleenor from Waynesville, NC
(Customer's Reviews) Tuesday, January 17, 2012

I've used several of these and they get the job done. My only complaints would be the odd dimensions (7/32 width in particular) and that it has a rod for the top piece instead of a flat bar. The price is great though.

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

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