METAL STEM & Threaded bowl
A simple attempt to show how the Falcon comes together:
The casting , fresh from the mould..this particular one carries ANA ANB and ANC nomenclature. The frames are clipped at the die casting works before shipping to Falcon factory.
On arrival the frame  is placed in a machine and the hole drilled for the smoke tube. Then it is polished 
Next take one mouth piece of whatever style required, (remember there are straight, dental and multi- purpose) and a plain piece of smoke tube  The tube is cut to length and the ends machined for a fit at both ends
Next the smoke tube is pressed into the mouthpiece . This is done by a press [A], therefore replacement by hand at home may result in a failure !.
Then the clever bit, the smoke tube is not twisted into a spiral, a cutter [B] is used to inscribe a spiral pattern on tube  internally and externally, creating a great surface area and a swirling of the smoke inside the tube.
Then the frame is placed in another press [C] and the mouthpiece/smoke tube assembly pressed into place.  After this the frame has the top of the cup machined for a smoother finish to ensure an air tight seal with the bowl. The frames and mouthpieces can then be bent in further machines when required.
The bowls arrive ready stained  and using machine [D] the Falcon speciality, the four start thread, is cut into the briar bowl , after which the bowl is stamped(currently 2007) with the word FALCON and the Falcon logo and the sealing ring fitted. The pipes are now ready for packing for shipping to retailers.
Not, unfortunately in the vast numbers of the earlier years, thanks to the seemingly world wide persecution of smokers and prohibition of smoking in just about every space where the pipeman would like to indulge. Currently it is allowed in the privacy of his own home but I am sure that the do-gooders are scheming ways to prevent even this. I personally make a point of having an empty and therefore unlit pipe in my lips when out and about, to the embarrassment of some snoopers and to show solidarity with the pipemen