Heat the frame and cool these parts, slide them in and let them return to normal temps. For sure it's not going to loosen. Be sure to use lubed-for-life bearings.
The OP was looking for the hole/internal thread. I think he needs to buy the taps, find a bike shop that will cut the thread, or just give the assembly to a machinist to single-point the mating part. http://www.parktool.com/blog/repair-help/bottom-bracket-tapping-and-facing-bts-bfs
In looking for terminology references I came across Campy using hirth couplings. For anyone but Campy I'd ask why, but if it's expensive and precise, Campy is the company to try it. They also made a wine bottle opener.
While many people concentrate on replacing the efficient chain drive on bicycles as some sort of design improvment, it is amazing to me the variety of ways developed to attach the pedals to cranks and cranks to the chainwheel and frame.