Do you have the table showing the relationship between tolerance on machined dimensions and surface roughness?

Yes, we supplied it with Machining v.2, and will include it with the next update of DFM Concurrent Costing. There is a general relation between surface roughness and the tolerance on the machined dimension. For example, a surface roughness on a turned surface of 16 microinch would generally correspond to a tolerance on the diameter of approximately +/- 0.0004 in. The relationships are presented here: