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Follow up on Colibri Precious Metal Tap and Die

I posted a question a few days ago about the colibri .6mm to 1.2 mm tap and die set.

Colibri claims that this tap and die set has a wider “jewelry” thread that is wider than watchmaker thread or metric fine thread, however I have not been able to find any information on TPI, pitch or angle. Does anyone know if there is a “Jewelry Thread” standard (I have seen the watch thread standards) or know perhaps the actual data for these colibri tap and dies.

I have not had success using general rules of thumb for selecting tap drill size for taps and rod/wire size for dies. Things don’t seem to fit like they should and I would like to know more about the specifications.

Thanks and thanks to those who replied to my earlier question.


I haven’t seen this book mentioned in either thread:

Taps, Drills & Dies (Inch & Metric): Useful Information for the Watch/Clock Maker and Model Maker by Robert Porter

This is an Amazon link to the paperback, but there’s also a Kindle version. I don’t know if it will help you with Colibri specifically, but there’s a lot of great info to help understand tap and die details.



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Hi Kirk, good luck with your problem.
I have Porters booklet and if I can find it I will get back to you. But I don’t think there is an answer there.
A common American thread is 4-40 which is about three millimetres in diameter and forty turns per inch.
So, at about 1.1 mm. by 40 TPI a machinist should have that possibility. From what I have seen I imagine that the missing top pitch is being lost with the fine detail from the wax to casting, to tumbling. A rolled thread would be the best way to go!!

Thank you John. I am making progress understanding the ins and outs of taps and dies (especially at these small sizes.) As I make progress and refine the process I will post what I learn.

All the best.


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