Schaller M6 90 Guitar Tuning Machine
The Schaller M6 90 guitar tuning machine represents high-precision instrument hardware engineered with an advanced 1:18 gear ratio for smooth, accurate, and stable tuning. Originally setting the benchmark for enclosed machine heads in 1966, this modern iteration incorporates CNC-machined components and high-grade brass string posts fitted seamlessly into the housing.
Equipped with a specialized stepped flange washer, this design automatically centers the string post through the banjo bolt and eliminates the need for stepped headstock drilling. This innovative structure removes tilting torque while protecting both the string post and rear mounting screws from excess tension.
Permanently lubricated with proprietary Schaller grease, each enclosed unit remains entirely maintenance-free over extended use. The M6 90 matches legacy mounting dimensions, allowing straightforward drop-in installation and replacement on existing instruments.
| Brand | Schaller |
| Model | M6 90 |
| Product Type | Guitar Tuning Machine |
| Gear Ratio | 1:18 |
| Post Material | High-Grade Brass |
| Button Borehole | 0.17 in (4.2 mm) diameter with 0.14 in (3.6 mm) drive flat |
| Weight per Single Tuner with Button (Small/Large) | Metal: 1.27 oz / 1.34 oz (36 g / 38 g), Perloid: 1.06 oz / 1.09 oz (30 g / 31 g), Ebony: 1.06 oz / 1.09 oz (30 g / 31 g) |
| Product Weight | 0.79 lb (0.36 kg) |
| Lubrication | Permanently lubricated with Schaller special grease |
| Flange Washer Diameter | 0.39 in (10 mm) |




















