Schaller M6 90 Guitar Tuning Machine
The Schaller M6 90 Guitar Tuning Machine sets an industry standard for enclosed machine heads, featuring an upgraded 1:18 gear ratio that ensures velvet-smooth tuning comfort and exceptional precision. Each component is CNC-machined to exacting tolerances, surface-treated, and driven by a self-locking mechanism that guarantees smooth, sensitive, and stable string tension adjustment.
Crafted from premium brass, the string posts fit seamlessly into the housing to maximize tuning stability and eliminate wear over time. The innovative stepped M6 washer centers the string post securely over the banjo bolt, removing tilting torque, relieving pressure from the rear mounting screw, and eliminating the need for stepped peghead counterbores.
Permanently lubricated with Schaller special grease, these maintenance-free tuning machines retain identical installation dimensions to their legacy predecessor for direct drop-in replacement without instrument modification.
| Brand | Schaller |
| Model | M6 90 |
| Product Type | Guitar Tuning Machine |
| Gear Ratio | 1:18 |
| Weight | 0.79 lb |
| Weight per Unit 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) |
| Button Bore Hole | Diameter 0.17 in with 0.14 in drive flat |
| Post Material | High-Grade Brass |
| Housing Design | Closed / Sealed |
| Lubrication | Permanent Special Grease (Maintenance-Free) |


















