What do I need to measure how deep to thread?

is there a chart that tells you how much to take off in inches when threading, organized by thread pitch? I figure that would be very helpful
 
Depth of thread equals 1/2 of thread pitch. (Only app;lies in 60º threads)

16 pitch thread is one thread every .0625 inches, half of that is .03125.

20 pitch equal one thread every .050 inches, half of that is .025.

And so on.,
 
So does this mean the depth of an M1 thread is 0.5mm?
 
The basic fact is that one cuts a thread until it nearly comes up sharp, then try a nut or gage on it until it fits, having lightly filed the OD to remove burrs.
 
That 1/2 of the pitch for depth is on one side of the thread. or the actual distance the cross slide must move the tool. Remember most lathes have the cross slide dial calibrated in amount removed from the diameter not the distane the tool is moving.
 
The book number for a sharp V is 0.866 * 1/tpi. This never seems to be deep enough for me.
 
The reason I'm asking is that I will be attempting some quad start M1 threads to screw two tubes together smoothly so I need to know how much extra metal on the outer dia of one tube the thread needs so there will be enough metal to cut the thread.
If I cut the female thread first then I am assuming the male needs to be 1mm larger dia for the thread to be deep enough.
 
successfully cut both male and female quad start threads but my calcs regarding the diameters didnt go well.
The threads were rough as they were single pointed with the hand crank in aluminium.
My tiny internal threading tool flexed a bit the the female thread tapers a tad.
I then had the thought of using a M6x1 tap as a cutting tool mounted in the tool post and cleaning up the threads.
This worked so well I believe it would be even better to fully cut the threads using the tap.
I will try again as I have a M12x1 tap that wont flex quite so much
As I want a quad start the geometry works spot on.
Now to refine my calcs on the tube diameters again and have another go.
 
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