Ryan, welcome to the world of kitless madness:biggrin:
If you plan on using your lathe to hold the work while threading with taps and dies ( best way ) then you 'can' do it without the proper tool holders but it makes it a little harder.
To tap; fit the chosen tap in the tailstock chuck and advance the tailstock quil fully so it disengages from the screw. You should still have about 2 inches of movement before it falls out.
With the work already drilled to match the tap and mounted in the HS chuck, slide the TS up to the HS. Hold the HS chuck and hand turn the TS chuck smoothly so the hole is tapped. When you un-screw the tap, be careful as the tap leaves the hole. If you pull on the chuck it can easily rip the first few threads.
Male threads with can be made the other way round provided that your TS chuck can handle the pen blank. Your die is unlikely to fit in the TS chuck. I would also cut any male threads before drilling any holes that need to go through them.
Mounting a narrow die in a scroll chuck isn't the best method and you need to take time to make sure it is aligned nicely. It is easy to be off a bit and it will ruin a thread.
Choosing the correct drill; Metric is easy, simply deduct the 'pitch' from the tap size and this is the drill you need. eg; M10 x 1.5mm tap= 10 - 1.5 = 8.5mm drill.
There are hundreds of drill/ thread charts available on the web for other threads.
I would suggest that you have a few practice goes on scraps before you attempt it on your new pen.
Tap and die holders are not very expensive and are a good investment:wink:
Hope this helps:biggrin:
