A truss rod wrench is the one tool that turns the adjuster inside a guitar neck, and the size and shape differ by maker. A 5 mm ball end, a 1/4 inch socket, a 5/16 inch socket and a slotted crank are not interchangeable, so the first job is knowing which nut you have.
The six wrenches below cover Martin, Taylor, Gibson-style, Fender bolt-on and heel-adjust designs, plus one multi-piece set. Sizes and fit lists come from each listing page. We have not used these tools ourselves, and fit claims are the makers’ own.
As an Amazon Associate we earn from qualifying purchases. Links below are affiliate links, and they do not change the product information we give.
What to Look For
| Feature | Why it matters |
|---|---|
| Size | The wrench must match the nut: 5 mm, 1/4 inch, 5/16 inch, 1/8 inch |
| Head style | Hex, ball end, socket and slotted crank reach different nuts |
| Fit list | Listings name the guitar brands each size suits |
| Handle | Grip, bumper and screwdriver extras affect ease of use |
Specs at a Glance
| Wrench | Size and head | Listed fit | Notes |
|---|---|---|---|
| MusicNomad MN236 | 5 mm ball end | Martin guitars, with exceptions | Steel; 1.7 oz |
| MusicNomad MN231 | 1/4 inch hex socket | Taylor headstock adjust; some Guild and Deering banjos | Carbon steel; magnetized screwdriver |
| MusicNomad MN232 | 5/16 inch socket | Gibson, PRS (USA), Gretsch and more | Carbon steel; magnetized screwdriver; 0.04 kg |
| Fender T-Style | 1/8 inch flat end Allen | Fender-style bolt-on truss rod adjustment | Rubber grip; 9.75 in long |
| StewMac Tele Crank | Slotted nut crank | Vintage-style Fender heel-adjust | Alloy steel; 3-9/16 in |
| Hilitchi 13 pc | 4 and 5 mm ball end; 7 and 8 mm box; 9 Allen keys | Many guitars per the listing | Carbon steel; 0.19 kg |
The 6 Best Truss Rod Wrenches
1. MusicNomad Premium 5mm for Martin Guitars
A 5 mm ball end wrench with an ergonomic handle for extra length and control, steel construction and the size laser etched into the metal. The listing says it fits all Martin models except the DSS-2018, OMSS-2019, Modern Deluxe Series and SC-13E.
Suits: Martin acoustics. Strengths: a ball end for deep access. Weaknesses: several Martin exclusions. Skip it if your guitar uses a socket nut.
View MusicNomad Premium Truss Rod Wrench 5mm for Martin Guitars (MN236) on Amazon
2. MusicNomad Premium 1/4 Inch for Taylor Guitars
A carbon steel 1/4 inch hex wrench with a protective rubber bumper for the truss rod opening and a magnetized Phillips screwdriver for small cover screws. It works on Taylor models that adjust at the headstock but not soundhole-adjust models, per the maker, and on some US-made Guild guitars before 2014.
Suits: Taylor headstock adjusters. Strengths: a bumper and screwdriver. Weaknesses: not for soundhole-adjust models. Skip it if you own an older Taylor nylon model.
View MusicNomad Premium 1/4 Inch Truss Rod Wrench for Taylor Guitars (MN231) on Amazon
3. MusicNomad 5/16 Inch Wrench with Screwdriver
A carbon steel 5/16 inch truss rod wrench with a comfort handle, a protective bumper for the headstock and a magnetized screwdriver. The listing says it works on Gibson, PRS (USA) and Gretsch guitars and more.
Suits: Gibson-style headstock nuts. Strengths: an included screwdriver. Weaknesses: a single size. Skip it if your nut is a different size.
View MusicNomad 5/16 Inch Truss Rod Wrench, Plus Magnetized Screwdriver (MN232) on Amazon
4. Fender T-Style Truss Rod Wrench
A T-style Allen wrench with a flat end 1/8 inch design, a rubber grip and a listed length of 9.75 inches. The product dimensions field reads 5.1 x 4.75 x 1.7 inches, which looks like the packed size, and the weight is 2.4 ounces.
Suits: 1/8 inch Allen truss rods. Strengths: a T-handle grip. Weaknesses: one size and few listing details. Skip it if you need a ball end.
View Fender Truss Rod Adjustment Wrench T-Style 1/8 Inch on Amazon
5. StewMac Truss Rod Crank for Tele
A compact 3-9/16 inch alloy steel wrench for slotted truss rod nuts at the heel, with straight and diagonal ends. The listing says it suits many vintage-style Fender guitars and basses, and that on a vintage-style Tele you only remove the pickguard.
Suits: vintage Fender heel adjusters. Strengths: small enough for a case. Weaknesses: only for slotted nuts. Skip it if your truss rod is at the headstock.
View StewMac Truss Rod Crank for Tele, Steel Wrench for Slotted Nuts on Amazon
6. Hilitchi 13 pc. Guitar Allen Wrench Set
A carbon steel set in a transparent box with 4 mm and 5 mm ball end truss rod wrenches, 7 mm and 8 mm pocket hex box wrenches and nine Allen wrenches in different sizes. The maker describes the ball ends as suited to narrow or deep adjustments such as on a Martin.
Suits: owning several sizes at once. Strengths: ball end and box types together. Weaknesses: metric only per the listing. Skip it if you need inch sizes.
View Hilitchi 13Pcs Guitar Allen Wrench Set with Ball End Truss Rod Wrenches on Amazon
Care and Use
- Identify your truss rod nut type before buying.
- Turn in small steps and recheck neck relief.
- Keep the wrench fully seated in the nut.
- Store wrenches with the case or the guitar tools.
Mistakes to Avoid
- Guessing the wrench size.
- Forcing a nut that does not move.
- Using an ill-fitting wrench that rounds the nut.
- Skipping the listed fit exclusions.
Truss Rod Wrenches FAQ
Which wrench fits a Martin?
The MusicNomad MN236 lists a 5 mm ball end for most Martin models, with several exceptions.
Which wrench suits a vintage Telecaster?
The StewMac crank is made for slotted heel-adjust nuts on vintage-style Fender guitars.
The Short Version
For Martin, the MusicNomad 5 mm. For Taylor, the 1/4 inch. For Gibson-style nuts, the 5/16 inch. For a 1/8 inch Allen, the Fender T-style. For a vintage Tele, the StewMac crank. For several sizes, the Hilitchi set.
