• Apprentice
    3 Apr 2024, 4:51 p.m.

    Dear forum reader!

    I need a little help: what IWC caliber belonged to this silver niello case? I upload some pictures from this case.

    Which is certain: on the case not found a push button, that the movement could be set from the crown (tirette). Measurements: the maximum diameter that can still fit in this case is 42.2 mm. I enjoy reading any new information.

  • Master
    4 Apr 2024, 2:48 p.m.

    This is a very tough question.

    The case is from around 1924 and the watch was an 'open face' pocket watch..The use of niello was not limited to just one year.

    In general the movement should be from 1920-1925. Rarely the movement and the case are from the same year.

    However ,we do not know whether the movement was '4,5,or 7 mm high.

    It could be cal. 52, 57 or 65.

    So, unfortunately no definite answer.



  • Apprentice
    5 Apr 2024, 9:27 a.m.

    Hi Adrian!

    Thank you very much for the quick reply! I thought it was a little earlier.
    Which serial number is usually smaller? The case or the movement? The iwc database writes the date 1921 for the movement number 770 thousand.
    If i write 770 thousand for case number, it gives two time intervals:

    1919-1923 750,000-800,000 alte IWC Liste compatible with new case index of 2002

    1920-1930 758,000-917,000 aktuelle IWC Liste compatible with old list from 2001

    Yes, it's not an easy question. I assumed that it had to be adjustable from the crown. And i search wich calibers were in use, which were already adjustable from the crown.

    The 52T has been in production since 1924, the 57T since 1926, and 65T since 1927.

    73 and 77 could also be considered.