Detail 01
18:1 lubricated gear ratio
The tuning mechanism is specified for smooth, accurate adjustment with minimal backlash.
Product detailSKU #1500000429994
GroverRoto-Grip Locking Super Rotomatics 509 Series Tuning Machines Chrome
Independent shopping perspective
The Korena take
Grover's chrome Roto-Grip Locking Super Rotomatics 509 Series tuning machines use a thumbscrew to secure each string at the post, making string installation and removal more direct. Their lubricated 18:1 gearing is specified for smooth, accurate tuning with minimal backlash, and the three-step button gives the set its distinct appearance. They are designed as drop-in replacements for a variety of popular tuner models, but the 25/64-inch post-hole requirement is the key installation measurement to confirm first.
Strong match
Who this is for
- Guitar maintenance where quicker string installation and removal is wanted through a locking thumbscrew mechanism.
- Replacing compatible popular tuner models after confirming the instrument has a 25/64-inch post hole.
Consider the trade-offs
When to look elsewhere
- Instruments that do not match the required 25/64-inch post-hole measurement.
What matters in use
The specifications, translated
Catalog numbers tell only part of the story. These are the details most likely to change how this product feels, sounds, or fits into a setup.
Detail 02
Thumbscrew string lock
The thumbscrew secures the string at the tuning post.
Detail 03
Chrome finish
This version has a chrome finish.
Final check
Know before you order
- 01Confirm the 25/64-inch post hole and compatibility with your existing tuner layout before treating them as a drop-in replacement.
Product questions
Before you decide
Straight answers to the questions shoppers most often ask about this product.
01How do the strings lock in place?
A thumbscrew mechanism secures each string at the tuning post.
02What post-hole size is required?
These tuning machines use a 25/64-inch post hole.
03What is the gear ratio?
They have a lubricated 18:1 gear ratio, specified for smooth and accurate tuning with minimal backlash.
