Truss Rod Adjustment: Which Way to Turn and How Far
Quick answer
Face the nut: clockwise tightens (less bow, lower mid-neck action), counter-clockwise loosens (more bow, cures low-fret buzz). Turn ¼ turn at most, retune, and wait before you measure again.
The truss rod is a steel rod inside the neck that controls how much the neck bows forward under string tension (called relief). Adjusting it is a normal, safe job if you go slowly. It does not mainly set action height or intonation.
1. Check relief first
- Tune to pitch.
- Press the 6th string at the 1st fret, and with your other hand (or a capo at fret 1) press it where the neck meets the body (around fret 14 to 17).
- Look at the gap between the string and the top of the 7th or 8th fret. A thin business card's thickness is roughly right.
| Instrument | Typical relief at fret 7-8 |
|---|---|
| Electric guitar | about 0.25 mm (0.010 in) |
| Acoustic guitar | about 0.1-0.3 mm (0.004-0.012 in) |
| Bass | about 0.3-0.4 mm (0.012-0.015 in) |
Check your maker's spec if it lists one; these are common starting points. Bass player? See the bass truss rod and setup cost guide.
2. Adjust it
| String touches frets / buzz on frets 1-5, gap at fret 7 is tiny | Too little relief: loosen (counter-clockwise) |
|---|---|
| Action high in the middle of the neck, big gap at fret 7 | Too much relief: tighten (clockwise) |
- Find the nut: under a cover on the headstock, inside the soundhole (acoustics), or at the heel.
- Use the right tool (usually a 4 mm, 5 mm or 1/8" Allen key, or a socket on Gibson-style guitars). Ask the maker if unsure.
- Slacken the strings a little before tightening; it is easier on the threads.
- Turn ¼ turn at most. Retune, wait a few minutes (an hour is better), and measure again.
- Repeat until the relief is right, then check action again with the action guide.
Tools
Bondhus hex key set
Covers the common metric and imperial truss rod sizes.
Best for: Most electric and many acoustic guitars
MusicNomad 5 mm truss rod wrench
Long reach through the soundhole.
Best for: Martin and other acoustics with a 5 mm soundhole nut
MusicNomad action ruler
Measures action and gives relief references.
Best for: Anyone doing their own setup
FAQ
Which way do I turn a truss rod?
Face the truss rod nut. Clockwise (righty-tighty) tightens it and straightens the neck. Counter-clockwise loosens it and adds bow.
How much should I turn a truss rod?
No more than a quarter turn at a time. Retune and wait before measuring again.
Does the truss rod change action?
A little, because relief moves the strings in the middle of the neck. Saddle height is the main action adjustment.
How often does a truss rod need adjusting?
Usually only with seasonal humidity changes or a change of string gauge or tuning.
Can I break my truss rod?
Yes, by forcing a stuck nut or overtightening. If it is very stiff, stop and see a tech.
Bass-specific relief and shop prices: bass truss rod and setup cost.
Neck moves with the seasons? Keep humidity steady: how to store a guitar · Humidipak vs Humitar.
Sources checked
- StewMac: truss rod adjustment (checked Oct 23, 2026): www.stewmac.com/video-and-ideas/online-resources/learn-about-guitar-an
- Taylor Guitars: neck relief and truss rod (checked Oct 23, 2026): www.taylorguitars.com/support/maintenance/neck-adjustment
- Fender setup guide (relief specs) (checked Oct 23, 2026): support.fender.com/hc/en-us/articles/212880686
FretCompare explains standard technique and setup practice in its own words. Specs are starting points; adjust to feel.
How this page was made
An editorial guide by Andrew from standard technique, manufacturer setup specs and the sources listed above. Not hands-on product testing. How we rate.