The Grover Mid-Size Locking Rotomatics 406 Series Machine Heads offer the same high-performance locking technology as the full-sized version, but in a more compact format.
Secure Locking & Finer Control
By reducing the button size, Grover has made it easier for players to adjust their tuning without their fingers feeling crowded, all while maintaining the classic Rotomatic aesthetic and robust build quality.
Plus, these tuners utilise Grover's proven locking system, which secures the string tightly to the post.
This design is perfect for players who use vibrato systems or engage in aggressive bending, as it virtually eliminates string slippage at the tuner.
Internally, the 406 Series is built with a high 18:1 gear ratio, providing exceptionally fine control for precise tuning.
The gears are also sealed and permanently lubricated, ensuring the mechanism remains smooth and reliable for the life of the instrument without the need for maintenance.
Balanced Design & Easy Installation
Because these tuners are "mid-sized," they are lighter than the standard locking models, weighing in at just 7.2oz for the full set.
This helps maintain the natural balance of your guitar and prevents the headstock from feeling too heavy.
They are designed as a direct drop-in replacement for Grover 305 Series tuners and fit standard 25/64-inch headstock holes.
The set comes complete with all the chrome-plated mounting hardware required—including bushings, washers, and screws—for a clean, professional-looking installation.
Grover Mid-Size Locking Rotomatics Machine Heads Features & Specifications
Internal locking mechanism for superior tuning stability and fast string changes
Smaller "mid-size" buttons designed specifically for 6-in-line headstocks
18:1 gear ratio for highly accurate and incremental tuning adjustments
Sealed-in, permanently lubricated gears for lifetime maintenance-free service
Fits standard 25/64 inch (approx. 10mm) diameter headstock holes
Shorter post length of 20.20mm to the hole with a 27.8mm total post height
Lightweight construction at 7.2oz per set for better instrument balance
Accommodates string gauges up to a maximum .054 gauge
Direct drop-in replacement for Grover 305 Series machine heads
Full set of six chrome-plated tuners in a 6-in-line configuration
Includes all necessary mounting hardware (bushings, washers, and screws)
Durable chrome finish built to handle regular professional use