zOwie Omega Discussion Forum

: I bought this watch recently and need a couple of small springs for
: the chrono function.
: I know that Omega and Tissot where sharing production for some
: years in the past so the parts I need may be
: the same as Omega. Can you please tell me what Omega cal. would
: this movement be?
: Thanks in advance.

Actually, neither Omega nor Tissot have ever manufactured chronographs. At the same time Tissot and Omega became associated (1926?), they joined forces with Lemania also.

Lemania is the manufacture of high end base movements and chronographs that is now known as Manufacture Breguet.

The well known Omega 321 and 861/1861 chronograph movements that are in "moonwatches" and went to the moon were actually Lemania movements.

You appear to have a Lemania CH 27 , also known as a Omega CH 27 (probably) T1, later (after the nomenclature changes in 1949) as a calibre 320. I cannot be certain at a glance, but if the movement diameter is 27 mm, it is nearly a sure thing. There have been three variations with differing parts in the 1940s; yours is likely one of the first two.

Lemania now calls this movement a 2310, although this designation actually indicates the version with a 12 hour counter.