# Tap question



## keithbyrd (Dec 14, 2016)

I want to start playing a bit with kitless pens.  So a basic question:
I have two triple start taps both M13x0.80 6H HS.  One is marked with a GD-4 and the other GD 5-  What is the significance of the GD 4 or GD 5?


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## edstreet (Dec 14, 2016)

Tolerance of precision they are made to.


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## keithbyrd (Dec 17, 2016)

Thank you Ed.  Now the next question(s).  Is there any significant difference between a 4 & 5?  Is the 4 more precise than the 5?


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## edstreet (Dec 17, 2016)

This may help you.  Short answer is 0.013mm difference. In all practical purposes there is no difference as both will do the job nicely.


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## keithbyrd (Dec 19, 2016)

Thank you Ed - I appreciate the additional info!


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