Watch Terminology Dictionary

Molybdenum is a chromium group element. Its symbol is Mo. Adding it to stainless steel increases its toughness, and mixing it with oil reduces the coefficient of friction. Lubricants containing molybdenum became popular in the watch industry in the late 1960s. The high-frequency automatic watches released around this time had strong mainsprings, and even when existing greases were injected into the barrel, they could not be expected to have a slip effect. However, molybdenum grease made it possible to prevent overwinding, even with strong mainsprings.