The "pitch" of a lead screw is determined by a) its lead and b) the number of independent screw starts. The lead
is defined by the axial distance the nut advances in one revolution of the screw. Pitch = Lead / Starts.
I believe that the larger KOP lead screw is
this model. If that's the case, the screw has a 0.125" lead. I believe it has 5 screw starts, but I can't find any data to verify this.
As for tapping this thread-- although it's possible in theory and practice, it would be easier and less costly to just buy a flanged nut from
the manufacturer and mount it as required.