I have an extensive tap & die set, but they're mainly designed for common bolt sizes.
The threads I need to cut are in (and on) metal and/or plastic pipes, or tubes; ranging between ∅49-89mm.
What's the proper way to cut these kinds of threads?
An exceptionally brief search for "pipe threader" revealed many options. Hand sets for under $100, powered models are available at most tool rental places.
PVC and ABS pipe is typically glued (ok, solvent welded) together. Threading typical schedule 40 plastic will probably weaken it enough that you may as well just push the joints together.
Cutting pipe is a completely different type of operation than cutting rod and bolts, with completely different techniques and tool sets. Not least, the threads are tapered.
Here in the States, the go-to manufacturer for pipe threading is "Ridgid". Can't speak for Europe.
The tools are fairly expensive, especially on large sizes . The tools can be rented, or if you are are careful, you can get your pipe dimensions and have the hardware store cut the thread when they sell you the pipe. You have to be very careful.
Treading is a heck of a lot of work. I rarely see new work done in threaded pipe unless it really has to. You may be better off transitioning into easier-to-work-with technology like plastic.
Some plastic pipe is threaded, but its purpose is either to transition to metal threaded pipe, or provide an easy point of separation. This is done with adapters which already have correct threads molded into them, and then they cement onto regular plastic pipe.