What You Need Before You Start
A 12-string guitar has six pairs of strings instead of six single strings. The four thickest pairs are tuned an octave apart—the thinner string sits above the thicker one—and the two thinnest pairs are tuned in unison. You will need a complete set of 12-string replacement strings (sold as a set, not individually), wire cutters, a string winder (optional but saves your hands), and a tuner. Clear a flat workspace and have good lighting so you can see what you are doing.
Before you begin, decide whether to remove all strings at once or replace them one pair at a time. Removing all strings at once lets you clean the fretboard and neck, but it removes all tension from the neck at once—fine for most guitars, but some players prefer the gentler approach of changing pairs one at a time. Either method works; choose based on whether you want to clean while you have access.
Key Takeaways
- A 12-string set contains six pairs of strings: four pairs tuned an octave apart and two pairs tuned in unison, so you must install them in the correct order or your guitar will sound wrong.
- Remove the old strings by loosening the tuning pegs until the strings go slack, then unwind them completely and pull them out of the bridge and headstock.
- Insert each new string through the bridge pin hole, pull it tight to the headstock, thread it through the tuning peg hole, and wind it so the string wraps downward around the peg post.
- Tune to pitch using a tuner, then gently stretch each string by pulling it away from the fretboard—new strings go flat quickly and need this break-in period.
- Expect new strings to drift out of tune for the first few hours of playing as they settle; retune every 15 minutes until they stabilize.
Remove the Old Strings
Loosen the tuning pegs on the headstock by turning them counterclockwise. Work your way across the headstock, loosening each peg a few turns at a time rather than loosening one completely, so the neck stays under even tension. Once all the strings are slack enough to move freely, unwind each tuning peg the rest of the way by hand until the string comes completely out of the peg hole.
At the bridge end, remove the bridge pins—the small pegs that hold the strings in place. On most 12-string guitars, you will find six bridge pins in a row. Gently pry each one up with a small screwdriver or the edge of a coin. Once a pin is out, pull the old string out of the bridge hole. Repeat for all six pairs. If you are replacing one pair at a time instead, loosen only that pair of tuning pegs and remove only that pair of bridge pins.
Understand the String Order
The six pairs on a 12-string guitar are not all the same. The thickest four pairs (strings 1 through 4, counting from the thinnest) are tuned an octave apart: one string is the normal pitch, and its partner is tuned one octave higher. The two thinnest pairs (strings 5 and 6) are tuned in unison—both strings in the pair play the same note.
When you open a 12-string set, the strings are labeled or grouped by pair. The package will show you which strings go together. If you are unsure, the thinner string in each of the four thicker pairs is the octave string; the thinner string in each of the two thinner pairs is the unison string. Installing them in the wrong order will not damage the guitar, but it will sound completely wrong, so take a moment to sort them before you start.
Install the Strings at the Bridge
Start with the thickest pair (the low E strings). Take the thicker string of the pair and insert it through the bridge hole on the bass side (the left side as you look at the guitar). Pull it through until about 2 inches of string hangs below the bridge. Lay the bridge pin in the hole on top of the string and gently tap it down with a screwdriver handle or mallet until it sits snug—do not hammer it; it should seat with light pressure. The pin holds the string in place and prevents it from slipping back out.
Now insert the thinner octave string through the same bridge hole, right next to the first string. Pull it tight and install its bridge pin the same way. Repeat this process for each of the remaining five pairs, working from the thickest strings toward the thinnest. Once all 12 strings are in the bridge and pinned, you are ready to thread them through the headstock.
Thread and Wind the Strings at the Headstock
Pull the thicker low E string up to the headstock on the bass side. Find the tuning peg hole for the low E string (usually the bottom peg on the bass side of the headstock). Thread the string through the hole, leaving about 2 inches of slack. Bend the string at a right angle just above the peg post so it wraps around the post as you turn the tuning peg.
Turn the tuning peg counterclockwise (when looking at the headstock from the front) so the string winds around the post. The string should wrap downward around the post, not upward—this keeps tension even and prevents the string from slipping. Wind until the string is snug but not yet at pitch; you will tune it precisely in the next step. Repeat this process for the octave string in the same pair, threading it through the same peg hole (or the adjacent hole if your headstock has separate holes for each string in a pair).
Work your way across the headstock, pairing up strings as you go. On most 12-string guitars, the two strings in each pair share a tuning peg or sit in adjacent pegs. Check your guitar's headstock layout to be sure. Once all 12 strings are threaded and wound loosely, trim the excess string at the headstock with wire cutters, leaving about a quarter-inch of slack so the string does not unwind.
Tune and Stretch the New Strings
Use a tuner to bring each string close to pitch. Start with the thickest pair and work toward the thinnest. Tune the thicker string of each pair first, then the thinner one. New strings stretch as you play them, so they will go flat quickly—do not expect them to hold pitch yet. Bring them to pitch, then move on to the next pair.
Once all 12 strings are at approximate pitch, gently stretch each one by pulling it away from the fretboard at the middle of the neck. Pull firmly but not violently—you are not trying to break the string, just pre-stretch it so it settles faster. After stretching, retune the entire guitar. The strings will have gone flat again. Repeat the stretch-and-retune cycle two or three times. This process helps the strings settle and hold pitch longer during the first few hours of playing.
Let the Strings Break In
New strings on a 12-string guitar drift out of tune faster than on a 6-string because there is more total string tension and more mass to settle. Expect to retune every 15 minutes for the first hour or two of playing. This is normal and does not mean something is wrong. Each time you retune, the strings will hold pitch a little longer. After a few hours, they will stabilize and hold tune much better.
Avoid playing hard or bending strings aggressively during the first hour. Gentle playing lets the strings settle without putting sudden stress on them. After the break-in period, your 12-string will sound fuller and brighter than it did with the old strings, and the tuning will be stable enough for regular playing and practice.
Frequently Asked Questions
Can I use regular 6-string sets on a 12-string guitar?
No. A 12-string set is specifically designed with the right gauges and pairs for a 12-string neck and bridge. Using 6-string sets will not fit the bridge holes correctly and will not produce the right sound. Always buy a 12-string set.
What if a string breaks while I am winding it?
Stop winding when ready and remove the broken string from the bridge and headstock. Replace it with a fresh string from the set. If you have already broken a string before finishing the job, you may have wound it too tightly or too fast. Slow down and use gentler tension on the remaining strings.
Do both strings in a pair need to be tuned to the same pitch?
No. The four thicker pairs have one string at the normal pitch and one an octave higher. The two thinnest pairs are tuned in unison. Your tuner will show you the correct pitch for each string—do not tune by ear or by matching the other string in the pair. Use the tuner for each string individually.
How often should I change 12-string strings?
That depends on how often you play. Light players may go three to six months; regular players usually change them every one to three months. Strings sound duller and lose brightness as they age, and they hold pitch less reliably. When you notice the sound getting dull or tuning stability getting worse, it is time for a fresh set.
Why does my 12-string sound tinny or wrong after I string it?
The most common cause is installing the octave and unison pairs in the wrong order. Double-check that the four thicker pairs have one string at normal pitch and one an octave higher, and that the two thinnest pairs are both in unison. If the pairs are correct and the sound is still off, the strings may not be fully seated in the bridge pins—remove and reseat each pin to make sure the strings are locked in place.