I need a bit of advice. I just had a job completed by a machine shop
that called for a 1/2" NTP and 1/4" NPT hole. The part was titled
"manifold". The parts just arrived with the 1/2" NPT hole tapped to the
bottom of a 1 1/8" deep port (will never seal)and a correctly tapped
1/4" NPT hole. The machine shop says it was my fault because I didn't
specify the thread length and I will now have to pay for a "rush run"
if I need to meet my deadline. Isn't NPT supposed to be tapped within a
certain range? Shouldn't they have asked if there was any doubt? I
think that they should have asked. Am I wrong?

Thanks,

RR