I can find formulas for turning, drilling, and milling, but none that cover the specific task of tapping. The specific HP is .67
I would like to make sure that I do not overload my spindle torque wise while I am low in the rpm's.
I will be using a Vega Gold, spiral point tap.
I don't have much hair left since starting this quest an hour ago.
Too many variables...
Could I suggest that you try a test where you setup on a manual mill, drill, then setup to tap with the machine in neutral. Set a point into a collet or drill chuck(to keep the tap square), and then affix the tap handle. Use a fish scale at the end of the handle to measure the force applied while tapping(keep the scale @ 90 degrees to the handle). To calculate torque multiply the applied force by the distance from where the scale is applied to the center of rotation.
Not fancy, not slick, but it will give you a real world value.
OR Google :tapping torque...
Can't Fix Stupid