Schaller M6 90 Guitar Tuning Machine
The Schaller M6 90 guitar tuning machine represents high-precision engineering with an optimized 1:18 gear ratio, delivering ultra-precise, velvet-smooth tuning and exceptional pitch stability. Every component is CNC-machined to exacting tolerances, surface-treated, and permanently lubricated with Schaller special grease for completely maintenance-free performance.
Crafted with premium brass string posts and a self-locking drive mechanism, this sealed tuner eliminates backlash and wear over extended playing sessions. The innovative stepped M6 flanged washer with a 0.39-inch (10 mm) base securely centers the string post via the hollow bolt, eliminating tilting moment and bypassing the need for stepped headstock drilling.
Engineered with identical mounting dimensions to its predecessor, the M6 90 allows for direct, modification-free drop-in replacement on electric and acoustic guitars. It provides maximum tuning comfort, robust durability, and reliable mechanical support for demanding musicians.
| Brand | Schaller |
| Product Type | Guitar Tuning Machine |
| Series | M6 Series |
| Model | M6 90 |
| Gear Ratio | 1:18 |
| Weight per Single Tuner with Button (Small / Large) | Metal (1.27 oz / 1.34 oz), Perloid (1.06 oz / 1.09 oz), Ebony (1.06 oz / 1.09 oz) including hollow screw |
| Product Weight | 0.79 lb |
| Button Bore Hole | Diameter 0.17 in (4.2 mm) with 0.14 in (3.6 mm) driving surface |
| Post Material | Brass |
| Lubrication | Maintenance-free Schaller Special Grease |



















