Stock tuners do an okay job until they don’t. String slippage, weather swings, and plain wear are the usual reasons a guitar drifts out of tune.
Locking tuners clamp the string at the post so it can’t unwind or slip. As a bonus, restrings drop from minutes to seconds per string.
We rated these ten sets on tuning stability, gear ratio, build, and ease of installation. Sperzel’s 6 In-Line takes the top spot, with strong options at every price below it.
New to the hardware? Our locking tuners explainer covers how they work.
The chart below compares all ten at a glance.
Quick Comparison Chart
| # | Product | Our Rating | ||
|---|---|---|---|---|
| 1 |  |
Sperzel 6 In-Line Locking Tuners | ★★★★★ | Check Price |
| 2 |  |
Planet Waves Auto-Trim Tuning Machines | ★★★★★ | Check Price |
| 3 |  |
Fender Locking Tuners Chrome | ★★★★☆ | Check Price |
| 4 |  |
Grover 102-18C Rotomatic | ★★★★☆ | Check Price |
| 5 |  |
Hipshot 6GLO Grip-Lock Tuners | ★★★★☆ | Check Price |
| 6 |  |
Guyker 6Pcs Guitar Locking Tuners | ★★★★☆ | Check Price |
| 7 |  |
Schaller Locking Machine Heads | ★★★★☆ | Check Price |
| 8 |  |
Grover 502C Roto-Grip | ★★★★☆ | Check Price |
| 9 |  |
Grover 406C Mini Locking Rotomatic | ★★★★☆ | Check Price |
| 10 |  |
Gotoh SD90 Locking Tuners | ★★★★☆ | Check Price |
From Drop-In Upgrades to Vintage Stealth
Gear ratios quietly separate these sets. Most run 18:1, the budget Guyker goes finer still at 1:19, and the vintage-style Gotoh SD90 sits at a coarser 15:1, which matters because a finer ratio means smaller pitch moves per knob turn.
Fit is the other dividing line. The Fender set drops straight into most Strats and Teles, the Hipshot 6GLO matches vintage screw holes with no new drilling, and the Gotoh hides its Magnum Lock inside Kluson-style keystone buttons that keep an old headstock looking stock.
1. Sperzel 6 In-Line Locking Tuners
Sperzel 6 In-Line Locking Tuners
Pro-grade inline locking tuners with staggered post heights that eliminate string trees and hold tune under heavy loads.
Pros
- Tune holds under hard playing
- Staggered heights skip string retainers
- Noticeably open, sensitive response
- Restring in seconds per string
Cons
- Removable pins can frustrate
- Some guitars need extra drilling
Sperzel has built custom machine heads since 1977 and supplies several big-name guitar companies, so the pedigree is real. The staggered post heights mean no string trees, and players consistently report the guitar’s tone opening up after the swap.
Restringing is the party trick: thread the string through the eye, pull it tight, lock, and tune to pitch. The wind never slips, even under heavy bending.
2. Planet Waves Auto-Trim Tuning Machines
Planet Waves Auto-Trim Tuning Machines
Innovative 18:1 locking tuners that automatically trim excess string as you tune, backed by a lifetime warranty.
Pros
- Built-in cutter trims strings for you
- Precise 18:1 tuning ratio
- D'Addario family build quality
- Lifetime warranty included
Cons
- Looks are more function than form
- Trimmer struggles on heavy gauges
Planet Waves is D’Addario’s hardware arm, and these tuners carry that value-first DNA. The headline feature is the auto-trim clamp: lock the string, tune up, and the excess gets snipped automatically.
An 18:1 gear ratio keeps tuning precise, and the lifetime warranty says everything about the build. Tremolo users in particular will appreciate how well these hold.
3. Fender Locking Tuners Chrome
Fender Locking Tuners Chrome
The locking tuners from Fender's American Deluxe guitars, sold as a six-pack upgrade for Strats and Teles.
Pros
- Standard on American Deluxe Fenders
- Drop-in fit for most Strats and Teles
- Complete kit with bushings and hardware
- Clean chrome suits most guitars
Cons
- Chrome finish isn't for everyone
- Won't fit American Vintage models
These are the same locking tuners Fender fits to its American Deluxe line, packaged as an upgrade kit. If your guitar has an inline-six headstock, installation is about as straightforward as this job gets.
The set ships with removable caps, bushings, and mounting hardware, and the 18:1 gearing tunes smoothly. For Strat and Tele owners who want factory-spec parts, this is the obvious pick.
4. Grover 102-18C Rotomatic
Grover 102-18C Rotomatic
The classic Rotomatic housing upgraded with 18:1 gearing for finer tuning, smoother action, and less backlash.
Pros
- Finer tuning with less backlash
- Lifetime sealed lubrication
- Adjustable-tension metal knobs
- Proven design since the 1960s
Cons
- Installation can be fiddly
- Needs 10mm peg holes
Rotomatics have been on headstocks since the 1960s, and the 102-18C keeps the classic housing while upgrading the gears to 18:1. The result is smoother, finer tuning with the backlash all but gone.
Cast housings and lifetime sealed lubrication mean these never need service. The box includes washers and wood screws for a clean install into 10mm peg holes.
5. Hipshot 6GLO Grip-Lock Tuners
Hipshot 6GLO Grip-Lock Tuners
Sleek Grip-Lock tuners with ultra-smooth action, vintage-compatible screw holes, and serious build quality.
Pros
- Ultra-smooth tuning action
- Locks hold strings dead tight
- Fits vintage-style screw holes
- Built to outlast the guitar
Cons
- Washers feel like an afterthought
- Costs more than budget sets
The 6GLO’s action is the smoothest here, with big gearing and easy-turning thumbwheels that lock the string down tight. Restring time drops dramatically once you’ve done it twice.
Hipshot purpose-designed the screw holes to match vintage spacing, so older guitars upgrade without drilling. The build is substantial enough that this is likely the last set you’ll buy.
6. Guyker 6Pcs Guitar Locking Tuners
Guyker 6Pcs Guitar Locking Tuners
Budget-friendly 1:19 locking tuners in three finish combinations that fit most modern 10mm headstocks.
Pros
- Finer 1:19 gear ratio than most
- Anti-corrosive, wear-resistant finish
- Fits Strat, PRS, and Les Paul types
- Strong value for the money
Cons
- Odd tuner can turn stiff
- Lacks the big-name pedigree
Guyker’s set is the value sleeper: a 1:19 ratio, finer than most big-brand sets, built for modern 10mm headstock holes. The finish is anti-corrosive and dustproof, and three color combinations cover most guitars.
Fit is generic by design, so Strats, PRS-styles, and Les Paul types all work. For the price of one boutique tuner you get the whole set.
7. Schaller Locking Machine Heads
Schaller Locking Machine Heads
German-made locking tuners found on high-end guitars, with 18:1 gearing and a knurled-nut locking mechanism.
Pros
- Fitted to many high-end guitars
- Knurled nut locks strings solid
- Holds tune in any conditions
- Simple insert-and-lock install
Cons
- Premium price tag
- Overkill for casual upgrades
Schaller machine heads show up on high-end production guitars for a reason: the German-made mechanism is about as solid as this hardware gets. A knurled nut clamps the string so it never needs multiple wraps around the post.
Installation is just insert, lock, and tune, and the pitch holds through weather, travel, and hard sets. If you want the prestige pick, it’s this one.
8. Grover 502C Roto-Grip
Grover 502C Roto-Grip
Roto-Grip locking Rotomatics with a one-wrap string lock, crisp response, and chrome, gold, or black finishes.
Pros
- Single wrap locks the string
- Crisp, clean tuning response
- Chrome, gold, or black finishes
- Natural Epiphone/Les Paul upgrade
Cons
- String seating takes practice
- Premium Grover pricing
Grover’s Roto-Grip system needs just one wrap around the post before the lock takes over, and the tuning response stays crisp. The name carries weight: plenty of veteran players check headstocks for it before buying a guitar.
Chrome, gold, and black options match any hardware scheme. It’s an especially natural upgrade for a Les Paul or Epiphone.
9. Grover 406C Mini Locking Rotomatic
Grover 406C Mini Locking Rotomatic
Mini locking Rotomatics with 18:1 gearing and smaller buttons for tighter headstocks and lighter weight.
Pros
- No slack left at the locking nut
- Prevents slippage and breakage
- Smaller buttons suit tight spacing
- Classic Rotomatic engineering
Cons
- Price stings for mini tuners
- Small buttons divide opinion
The 406C shrinks the Rotomatic formula into a mini housing: the same 18:1 engineering with smaller buttons for inline-six headstocks and players who like more finger room.
Installation is thread, pull tension by hand, done. The lock leaves no slack at the nut, so strings stay tensioned exactly where you set them.
10. Gotoh SD90 Locking Tuners
Gotoh SD90 Locking Tuners
Vintage Kluson-style keystone tuners hiding Gotoh's Magnum Lock system, with a 15:1 ratio and nickel finish.
Pros
- Vintage looks, modern locking
- Smooth and stable through big bends
- No drilling on 8.8mm holes
- Press-fit bushings included
Cons
- Buttons sit differently than stock
- Larger holes need adapter bushings
The SD90 is for vintage purists: Kluson-style keystone buttons and a nickel finish over Gotoh’s discreet Magnum Lock mechanism. Nobody can tell your Les Paul went modern.
The 15:1 ratio tunes smoothly and survives big bends, and 8.8mm holes need no drilling at all. Larger 9.5 to 10.5mm holes just take adapter bushings.
Final Thoughts
The Sperzel 6 In-Line is the set we’d put on most guitars first: pro heritage, no string trees, and a lock that simply doesn’t slip.
The Planet Waves Auto-Trim is the clever value pick with its built-in string cutter, and Fender owners get a factory-spec upgrade in the chrome set.
For vintage instruments, the Gotoh SD90 adds modern locking without changing the look, while the budget Guyker set still beats the stock tuners on most guitars.
Once your strings stay put, keep them accurate too with our best guitar tuner picks. And when it’s time for fresh strings, our string changing walkthrough makes the job painless.
