ingenieur 866 with sigma dial

these are my ingenieur 866 with sigma dial, what other types of dials with the
sigma symbol do you know?

Hi Giuliano,

I have only seen the Sigma dial on vintage Ingenieurs ref. 866.

Never on a 666 or 766. This is not so strange as it was used between
1970-2003.

Not only IWC but also Rolex, Patek and Vacheron Constantin used it as a qualty
mark for the use of golden hands and indices.

There is an interesting article on Hodinkee about the history of the Sigma
dial.

Regards,

Adrian,

(alwaysiwc)

Hi Adrian, thank you for your comment, but what I am asking to the members was
a little bit different.

I know enough the story of the sigma dial ( BTW I owned also a Bulova with
this symbol), but my question was: among the ingenieur 866 what and how many
different dials were used applying the sigma symbol.

For example do it exist an ingenieur black dial with sigma symbol? In
according with my knowledge only three dials were used with sigma symbol, that
are the blue, the silver and the grey/blue, made between the 1972 and 1974,
but I am not sure of this, and for this reason I have posted my question.

Of course we are always talking of the ingenieur 866.

Thank you for your comments