Drafted Parallel Surfaces - Dimensioning Method

[jausfeld]

I am probably opening a can of worms here but I have run into this problem several times before and I have not come up with a good answer on how to properly dimension the attached situation.

The question is directed at the .110 boss height dimension in the attachment. Both the top surface and the bottom surface are bifurcated draft planes originating from the parting line in this cast part. In this case the top surface and bottom surface are drafted but parallel to each other. This means the .110 technically does not change along the two reference surfaces.

There tends to be two camps here on how to handle it. One, could state that because the dimension does not change along the draft planes there is no effective draft and it should not be noted in the dimension. The second would acknowledge the first camps point but put it in anyway as a -DFT as shown letting the tool maker know these are drafted surfaces.

I would like to know what you think. Perhaps there is a generally accepted method here.

[Kelly_Bramble]

I'm not sure exactly what your question is on regards to the illustration you have shown. Perhaps more detail in your illustration?

If your goal is to dimension and tolerance the two surfaces parallel to each other, then a simple limit tolerance with the desired tolerance variable is the answer.