Tissot 27B-21 - crown tap no.

[Khan]

Dear enthusiasts

I measured the stem thread to be approx. 1.05 mm. When I choose a crown, should I go for tap 10 (1.00 mm) or tap 11 (1.10 mm). Correct me if I'm wrong in conversions. 

Cousinsuk sells new Tissot crowns but these are standardized tap 9(0.90 mm) and unfortunately not compatible. The watch is from end 40s. 

Thanks for helping. 

Edited May 21, 2019 by Khan

[Chopin]

When in doubt I go for the larger size... I'd say get the tap 11.

[HSL]

That Crown would look strange on a 40's Tissot. I know some change to a Tap 9 stem and go with it but personaly I would wait until the correct one shows up. Which model of the 27B-21 do you have? Some pictures would be nice, one never know someone here might have just the right one .

B.T.W If you messured 1.05 the size is probably Tap 11.

[Chopin]

Indeed that is not the correct style for a 40s watch... Have you tried eBay ?

[Khan]

Thank You guys for responses.

Here's a picture. The existing long piped crown is not deep enough to fit the tube on the case.

The winding is a litte stiff despite service, so would prefer not to go down in thread size.

I'm a little confused by tap conversions, seems it's different from US and UK?

I found some on eBay Spain by typing 'tissot vintage crown's but not sure of them yet relatively pricy. 

Edited May 21, 2019 by Khan

[rogart63]

Cousinsuk have there own size chart. Which i think is the best. Esslinger have the right one that most other use. U should need a tap 8 crown. As for the crown. older Tissot used a domed crown without logo. 

 

Watch Stem Tap Chart _ mm Size Reference Chart _ Esslinger.com _ Esslinger Watchmaker Supplies Blog.html

Edited May 21, 2019 by rogart63

[jdm]

12 hours ago, rogart63 said:

Watch Stem Tap Chart _ mm Size Reference Chart _ Esslinger.com _ Esslinger Watchmaker Supplies Blog.html 53.4 kB · 1 download

You've posted a broken HTML page, not the actual chart.

[rogart63]

Oopps . Hope this works better. 

https://blog.esslinger.com/stem-tap-mm-size-cross-reference-chart/