There is nothing wrong with this method, but what if you have many holes to check on a production part ? Very time consuming. You are correct, there is no way to know where the threads start, thats why the pitch function works so well. whether your first point is on the crest, or half way in between, it doesn't matter, it hits in that same spot all the way up coming out of the hole. making sure you have a proper probe diameter and you are golden....some people in this thread seem to doubt the reliability or accuracy of this method, well, knock yourself out, do it your way...its like banging your head on a wall...
+1 I like this method also I think the issue some people run into is the quality (surface finish) of the thread. I imagine like most places I've worked at in this trade most people cut there threaded holes with a tap. and depending on alot of variables (type of material, different taps, machine,ect). The facility I'm at now have two work arounds. Use a thread mill, this usually should produce a nicer thread then a tapped hole and are other work around is tap the hole after its checked. I know the second ones cheating if the print has the fcf on the threaded holes but I leave it up to the customer if there okay with the method its checked. Then I'm okay with it.
There is nothing wrong with this method, but what if you have many holes to check on a production part ? Very time consuming. You are correct, there is no way to know where the threads start, thats why the pitch function works so well. whether your first point is on the crest, or half way in between, it doesn't matter, it hits in that same spot all the way up coming out of the hole. making sure you have a proper probe diameter and you are golden....some people in this thread seem to doubt the reliability or accuracy of this method, well, knock yourself out, do it your way...its like banging your head on a wall...
+1 I like this method also I think the issue some people run into is the quality (surface finish) of the thread. I imagine like most places I've worked at in this trade most people cut there threaded holes with a tap. and depending on alot of variables (type of material, different taps, machine,ect). The facility I'm at now have two work arounds. Use a thread mill, this usually should produce a nicer thread then a tapped hole and are other work around is tap the hole after its checked. I know the second ones cheating if the print has the fcf on the threaded holes but I leave it up to the customer if there okay with the method its checked. Then I'm okay with it.
