How to use the watchmakers thread die plate?

[szbalogh]

My friend went abroad for a while and for this time he gave me the set similar to this. 

I want to make my own thread taps with it. 

As one can see there are two series of threaded holes on it for each size. Which one is should be used or which one should be used first?

[szbalogh]

Aniway, i made my first tap with the die in the set. M1.8, first tested in brass. It does the job. Will test it in steel tomorrow. 

It has not so sharp edges i would like to see however..

 

[RyMoeller]

I believe the double hole is used for cutting threads and the single hole adjacent is used if you are cleaning up threads that have been damaged.  

[szbalogh]

4 hours ago, RyMoeller said:

I believe the double hole is used for cutting threads and the single hole adjacent is used if you are cleaning up threads that have been damaged.  

Thank You! This was also my first tought. An then i  was thinking thatmaybe one is to get the most material off and the other to make the final thread. You are right, the tap i made screws perfectly on the single hole, no more material was removed here.

Today i will make another try to make a new tap. The one on the pictures was made with the number 18 and the tap has only 1.73mm diameter at the threads which are not so sharp at the tips. Maybe the rod was to thin. 

[praezis]

Topic was discussed just recently here.

Frank

[szbalogh]

4 hours ago, praezis said:

Topic was discussed just recently here.

Frank

Thank You Frank! The diameter of the stock rod is not a question. Today i made an other try. The rod was 1.79mm and after threading i ended up again with an 1.73 mm dimater tap. This is a real cheap die so i can imagine that it is not producing perfect threads. 

Tomorrow i will try to make the die with the tap from the set and check if it makes better threads. 

The steel i am using is really soft annealed and glass hard if hardened. The tap i made yesterday was cutting thread in soft steel easily  I plan to make the dies from steel saw blade which is basicly carbon steel also.