I do a lot of thread milling.
Anything that has short threads gets milled instead of screwcut.
Because I'm tight and begrudge spending mega$$ for a thread mill I use my own.
Small threadmills are just taps with all the flutes except one ground off.
Larger ones are just one insert out of a Coventry die head mounted in a holder.
With an example piece that's been milled in one pass.
That same holder also serves as an internal threading tool on the lathe.
John S.