Schaller M6 90 Guitar Tuning Machine
The Schaller M6 90 delivers exceptional tuning precision and stability with an upgraded 1:18 gear ratio for smooth, velvety operation. Setting the global standard for enclosed machine heads since 1966, this refined iteration integrates CNC-machined components and high-grade brass string posts engineered for maximum durability and wear-free performance.
Featuring the innovative stepped M6 flanged washer, this machine head centers the post through the banjo bolt and eliminates tilting torque without requiring a stepped headstock bore. The self-locking internal drive mechanism is permanently lubricated with Schaller special grease, providing completely maintenance-free functionality over its entire lifespan.
Sharing identical mounting dimensions with its predecessor, the M6 90 serves as a direct drop-in replacement that requires no headstock modifications. It provides professional-grade tuning accuracy and rock-solid pitch stability across diverse configurations for demanding guitarists.
| Brand | Schaller |
| Model | M6 90 |
| Gear Ratio | 1:18 |
| Post Material | Brass |
| Manufacturing Process | Precision CNC-machined |
| Lubrication | Schaller special permanent grease |
| Button Bore Hole | 0.17 in (4.2 mm) diameter with 0.14 in (3.6 mm) drive flat |
| Flanged Washer Diameter | 0.39 in (10 mm) |
| Mounting Screw Size | M2.2 x 0.37 in (9.5 mm) |
| Single Machine Weight (Metal Button Small/Large) | 1.27 oz / 1.34 oz (36 g / 38 g) |
| Single Machine Weight (Perloid/Ebony Button Small/Large) | 1.06 oz / 1.09 oz (30 g / 31 g) |
| Product Weight | 0.13 lb |




















