I work in a shop with about 50 employees. Theres only 2 CNC lathes. The guy that ran them before me quit and went else where, needless to say he was the only one who ever ran them and when he quit he used his week vaca for one of the 2 weeks. So i just got the quick run around cuz he didnt care. So far ive been mainly makin it up as i go and doing good so far. But getting stumped on NPT thread. All the other NPT we made was for 'joe blow' plumber down the road, where as long as it works it worked. The part i have to make is for an aerospace company so it has to meet a taper gage and thread gage. I know i need an "I" value in the G76 but when i look at the previous programs and compare it to the handbook, i dont have a clue where hes getting his X, I, K values from. Like i said before we made them for plumbers so who even knows if his values are right anyways. As for boring do u just bore the .75/foot taper?

Some explanation and examples would be great and where u got them from like machinist handbook etc.

Part i need to make needs a 1/2-14 NPT, .551 deep in SS.