I came up with .0022 Sq In in the cross section of a 12 pitch thread, which required .242 HP @ 16 SFPM. Just seems much lower than what I had expected...
I can tell you how much torque you will need - but since I don't have the torque spec for that machine you will have to figure out if it has enough yourself.(With tapping it's torque that counts).
Torque = K*Ct*Cm
Where K = material factor
Ct= tap condition multiplication factor
Cm = torque constant (metal removed per rev)
For 150 BHN Steel, k = 290000 in lbf/in^3
400 BHN Steel, k = 500000 in lbf/in^3
For a sharp spiral point tap, Ct = 1.0
For a dull straight flute tap, Ct = 2.5
For a 1.625-12 Tap at 75%, Cm = 0.00099 in^3/rev
So assuming some kind of steel, torque required will be anywhere between 24 ft lbf and 103 ft lbf. Your machine should be able to deliver that much torque.
