Aaron’s method is good but not so easy if you want to accurately replicate threads to specifications. Also the internal threads have different specs than the external ones.
As for the termination, in the tutorial Cotty referred to, I only cut them off flat which isn’t really correct. On the tap wrench, I added the chamfer which would be appropriate for the way the real threads would be done.
That’ll explode the polygon count. I’d be interested how you made it, and particularly tapering it off. I’ve had a similar situation I wanted to post a question for.
The main part of the kurling is made up of a bunch of components. I intersected the tapered part of the handle with the diamonds where the knurling runs out and deleted the tops of the diamonds basically mimicking the process on the lathe. I exploded the diamonds before trimming instead of leaving them as components.
FWIW, I converted the truncated diamonds to individual components instead of a mass of loose geometry within the handle component. Reduced the file size by nearly 20%.
This Old Tony’s tap wrench (you didn’t do the knurling! or the centrum hole on the handle end). Did you do the metric one or the Imperial measurements?