4. The ID taper on this part is a National Pipe Taper.

What is the definition of a National Pipe Taper?

Calculate the ending bore diameter.

Solution:

step 1.  National Pipe Taper = 3/4” in diameter per foot of length

             tan angle = opp /adj

            tan angle = 0.75” / 12”

            NTP angle = 3.576 degrees

            Now divide the angle to find the angle per side.

            3.576 / 2 = 1.788 degrees

step2.  find triangle

step 3.  label known & needed

step 4.  select trig rule = use TAN

step 5.  tan angle = opp / adj

             tan 1.788 = opp / 0.8847

             opp = 0.0276

step 6.  find unknown :  0.950 – (2x 0.0276) = 0.8948