The BM12-1975M is the manual-winding base caliber of the Baumatic family, designed by Manufacture Horlogère ValFleurier for Baume & Mercier. It was the first to feature the innovative TwinSpir hairspring - a composite balance spring combining two layers of silicon at alternating 45-degree angles, bound by a silicon dioxide layer for thermocompensation. This movement debuted in the Clifton Manual 1830 and serves as the foundation for the automatic Baumatic variants.
Movement Type
Manual Wind
Jewel Count
18 jewels
Power Reserve
90h
Frequency
28,800 vph (8 Hz)
Diameter
28.2mm
Height
4.2mm
Display Type
Analog
Shock Protection
Incabloc
BRAND
Baume & MercierTYPE
Manual WindSTATUS
In ProductionMANUFACTURE
In-houseLAUNCH YEAR
2017CALIBER FAMILY
BaumaticCOUNTRY
SwitzerlandALSO KNOWN AS
