Schaller M6 90 Guitar Tuning Machine
The Schaller M6 90 guitar tuning machine represents high-precision engineering with an upgraded 1:18 gear ratio for smooth, accurate tuning. Designed as the direct evolution of the legendary original sealed tuner first introduced in 1966, it incorporates state-of-the-art manufacturing while maintaining standard installation dimensions for seamless retrofitting without modifications.
Every internal component is CNC-machined to exact tolerances and surface-treated for maximum wear resistance. High-grade brass string posts and self-locking drive mechanisms ensure exceptional tuning stability, while the permanently lubricated sealed housing requires zero maintenance throughout its lifespan.
Featuring the innovative stepped M6 flanged washer, this tuning machine reliably centers the string post via the banjo bolt with a 0.39 in (10 mm) diameter base, eliminating the need for stepped headstock boreholes. This design absorbs rotational stress and distributes pressure away from both the post and rear mounting screws to protect the instrument.
| Brand | Schaller |
| Model | M6 90 |
| Product Type | Guitar Tuning Machine |
| Gear Ratio | 1:18 |
| String Post Material | High-Grade Brass |
| Housing Type | Sealed, Permanently Lubricated |
| Button Bore Hole | Diameter 0.17 in (4.2 mm) with 0.14 in (3.6 mm) drive flat |
| Mounting Screws | M2.2 x 0.37 in (9.5 mm) |
| 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 banjo bolt |
| Product Weight | 0.79 lb |




















