Schaller M6 90 Guitar Tuning Machine
The Schaller M6 90 guitar tuning machine delivers outstanding precision and tuning comfort with its refined 1:18 gear ratio. As an evolution of the industry-standard closed tuner design established in 1966, this model features high-precision CNC-machined components and surface finishes that ensure smooth, sensitive, and stable tuning performance.
Equipped with high-grade brass string posts precisely fitted into the housing, the M6 90 ensures maximum tuning stability and wear-free operation. The closed housing design is permanently lubricated with proprietary Schaller grease, providing completely maintenance-free functionality over its entire lifespan.
Featuring the innovative stepped M6 collar washer with a 0.39 in diameter, installation is streamlined by securely centering the string post without requiring stepped drilling in the headstock. This configuration eliminates tilting moments and relieves mechanical stress on both the string post and rear mounting screws while maintaining identical installation dimensions to predecessor models for effortless replacement.
| Brand | Schaller |
| Series | M6 Series |
| Model | M6 90 |
| Product Type | Guitar Tuning Machine |
| Gear Ratio | 1:18 |
| String Post Material | Brass |
| Button Borehole Diameter | 0.17 in (4.2 mm) with 0.14 in (3.6 mm) drive flat |
| Collar Washer Diameter | 0.39 in (10 mm) |
| Mounting Screw Size | M2.2 x 9.5 mm (0.09 x 0.37 in) |
| Weight | 0.79 lb |
| Lubrication | Permanently lubricated with Schaller special grease |




















