Hour and Minute Hands
The Heuer 3646 1st execution dial was produced with three different hands:
- “Full lume” dauphine hands, which are commonly known as “1st execution”
- Steel edged dauphine hands filled with lume, pointed; this style is commonly known as “2nd execution”, I refer to below as “pointed lume”, and their introduction coincides with the serial numbers of the last hand style,
- Same dauphine hand shape as #2, above, though with thinner lume, rectangular in shape on the hour hand, and coming to a point on the minute hand. I refer to this as “2nd execution” also as the timing for release is the same as the above, but note as “rectangular lume.’
Side note: we do see some overlap in hands, with serials for 3646 with full lume (1st execution hands) extending into the serials for 2nd execution hands.
This research is focused on the second execution hands (#2 and #3, above).
Within this set of non-full lume dauphine hands, we see an example with larger luminous area (#2) appearing on a lower serial number than the hand with thinner rectangular lume (though only one example, and a bit of an outlier). The use of the hands with thinner luminous area is limited in time (488xx-489xx), while we see the hands with larger luminous area span from 487xx-526xx.
The hour hand of the 2nd execution hand, and we also see this on the 2446, often shows signs of rust, whereas the minute hand does not. I do not know whether this is due to the larger steel surface area of the hour hand, or due to different type of steel used.
Chronograph Hand
Most are familiar with the white chronograph hand of the Heuer Autavia 3646. However, we also see red chronograph hands. In cases where the Heuer Autavia 3646 has a red chronograph hand, we see the main hands featuring the thinner lume. There are cases where the hands with thinner luminous area are paired with white chronograph hands, though nearly all of those cases appear to be replacements, otherwise incorrect hands, or on watches that have been clearly restored in some way (such as relumed main hands). It is difficult to say if thin lume main hands and red chronograph hands were always paired together, but without a larger data set I would say that they were intended to pair in that manner.
We also see a single example of thin rectangular lume hand paired with a white chronograph hand that has a leaf at the end. Given I have seen just one of these to date, I am inclined to believe this is a replacement hand.