I’ve looked for clear information on flat tail hand dimensions and haven’t really found much. I’ve got three Tritium flat tail hands that initially look to be all the same, but on closer inspection there is one that is fractionally longer than the other two. Measuring as best as I can I get one at 18.80mm and the other pair at 18.30mm. In MWO there is no mention of lengths in the main hands section, but the Ultraman orange hand is described as 18.80mm so I concluded that my 18.80mm hand is probably an original hand. The other two might be Tritium service hands (which I understand can be slightly shorter).

Does anyone know if this is documented anywhere, or am I left to I only speculate...



18.80mm in the middle. 18.30mm either side.

 

Interesting post. I’m assuming the shorter hands are NOS? I ask because I understand sometimes watchmakers will nip the ends to make them fit better under the crystal.

 

That’s an interesting point. As far as I know they are NOS. I’ll take a look at them under the loupe and see if there’s any evidence that the ends having been snipped.

 

Well, not this watchmaker! If it’s the correct hand for the watch, no such modification should be required.

If anything, the hand would be curved down slightly.

 

I checked all three and can see no perceptible difference at the tips. All are very cleanly and squarely ended, no paint chipping or loss, no twisting, nothing to indicate cutting.

@Archer I saw you’d chipped in with measurements on an old thread about Speedy Pro vs. Speedy MK2 hands, but that thread couldn’t really help with the question about the flat tail sweeps. Can you say anything about the lengths ?

 

Well, if I search on hands for say the 861 movement, I get 88 results (note that hour and minute hands are sold in pairs, so each pair is just one result).

If I limit those to just the chronograph seconds hands, that still leaves 18 different hands.

If I then limit the selection to just white hands of this type, that leaves just 2 options - these are current hands.

Hands are measured from the center of the mounting hole to the tip, so not the overall length as you are doing, and how MWO does it.

Looking at the two options for these hands, one version is 14 mm, and the other is 14,75 mm.

The short hands are for the Speedmaster Mk. II watches, and the longer are for the regular Speedmaster Pro versions.

If I had to guess, I would say the short hands are Mk. II hands, and not Speedy Pro hands.

Cheers, Al

 

That’s very useful info... thanks !

So with my calipers set and locked at 14.75mm, this is the long hand (top) and one of the two short hands (bottom). Obviously the long one appears to be a good match, the short one, well, falls short



And now with the calipers reset to 14.00mm this is the short hand.


Personally I’d say that’s it’s fractionally too long, but absolutely no doubt it’s much closer to 14.00mm than 14.75mm. So yes probably one Pro hand and two Mk. II hands. How on earth most sellers tell the difference is beyond me.

 

OK I tried to come up with a quick visual test. On my shorter hands distance B is pretty much double distance A. For B use the far tip of the lume and the back of the hand. For A use the tip of the hand and the transition at the back of the arrow head. For my long hand it is clearly less than double. Might be a useful tool if you’ve only got a picture, but of course it needs to be a very good “head on” picture otherwise the perspective will mess it up.



Edit for clarity... This double rule seems to work for the Mk. II hands. A Pro hand should have a longer “A”, so A.2 would be a fair bit longer than B. I’ll run some checks on images in MWO.

 

From MWO hand type C.2
On my screen A is 5.4cm and B is 10.4cm, so it kind of works (A is more than half of B).

 

In the end it’s getting confusing

These are my two hand types against the reference from MWO. I’ve scaled as best as I can so that the overall length is the same. I’d say my shorter hand is a much better match in terms of proportions. My long hand obviously has a relatively longer tip as the lume cut outs no longer line up.

Short hand vs. C.2


Long hand vs. C.2

 

Interesting detective work, well done . Is there any chance of any discrepancies between different batches, as an explanation for the differences?

 

I considered that but just don’t know enough to say. My feeling is that a 0.75mm difference in length (post center - tip) would be too great. It doesn’t sound a lot but would be pretty noticeable at the seconds track on a dial. As an example it’s very noticeable when an Ultraman hand is correct or not.

The difficulty is that the watches in question are all old now, and unless you’re certain a particular example is all original then you can’t use them as references. Also crystal distortion means I don’t like to try and measure on watches. I think it’d be very nice to understand though. I’m sure a lot of hands that are sold as “pro” hands are actually Mk.II hands (either knowingly or unknowingly).

Did anyone else here try to figure this out ?

 

And with these macro pics I’m starting to think my three have been re-lumed. Doesn’t look as neat as the MWO hand...