Schaller M4/BM Light Bass Tuning Machine Button
The Schaller M4/BM Light Bass Tuning Machine Button is a precision-engineered replacement component designed specifically for bass guitar tuners. Built to exacting German engineering standards, it offers a secure fit and smooth operation to restore or customize your instrument's tuning machines.
This replacement button is fully compatible with Schaller M4 and BM Light series bass tuning machines. It features a bore hole with an inner diameter of 0.17 in (4.3 mm) and a drive flat measurement of 0.15 in (3.9 mm) from flat to flat for reliable torque transmission.
Supplied as an individual tuning button, it is designed for installation using the existing mounting screw from your tuning machine assembly. It provides an authentic factory fit and finish for instrument repairs, maintenance, and restorations.
| Brand | Schaller |
| Product Type | Bass Tuning Machine Button |
| Compatibility | Schaller M4, Schaller BM Light |
| Bore Inner Diameter | 0.17 in (4.3 mm) |
| Drive Flat Dimension | 0.15 in (3.9 mm) flat to flat |
| Product Weight | 0.02 lb |
| Includes | 1 x Tuning Machine Button |






















