The metal lathe can play a huge role in pipe making. If large enough, it can be used for stummels as well as stems. Many pipe makers have both metal lathes, and wood lathes, others have only one or the other, and still others have multiple metal lathes set up for different procedures. For a complete description of the metal lathe, see the (Wikipedia link).
The main advantage of metal lathes over wood lathes is the tool carriage, which moves the cutting tool precisely at any angle relative to the work. This is nearly essential when cutting stem tenons, for example. Many pipe makers also use this feature to rough in stummel shapes, using it freehand, sort of like the old Etch a Sketch (children's toy). It is also possible to set up a wood lathe type tool rest on a`metal lathe, which allows the use of wood lathe tools.
Full size metal lathes
Mini metal lathes
I have a Taig, micro metal lathe, and micro it is! For those that are familiar with metal lathes, they would be socked at how small this lathe is. This is it greatest feature and it greatest weakness. Considering the price, this is a wonderful little tool. It is used to turn the tenons on stems to the precise diameter needed for a good fit between stem and stummel. It is also a key tool for doing stem inlay work.
A full-sized, metal lathe is the pipe makers pipe tool. If you have the funds, and want to skip to "the real deal" a nice metal lathe is the tool of choice. Not only can you turn and drill stummels on it, put you can turn the tenons for your stems as well. This is the main tool I would like to upgrade in my shop. A nice, used Atlas metal lathe from the 1950's or so, can be had for about $500 or $600 bucks, and would replace both my Delta Midi Lathe and my Taig.
Many people, like me when I was trying to figure out what tools I needed to start pipe making, do not know the difference between a metal and a wood lathe. The difference is mainly one of precision. I wood lathe has only a bar upon which to rest chisels that you operate by hand to shape the wood. A metal lathe, by contrast, has a tool carriage that precisely move a cutting bit along a constant, though adjustable, diameter. Both a wood lathe and a metal lathe will turn a variety of materials, they simply derive their name from the material that are most often used for.
Coming back to what I use for the precision work needed for turning a good tenon, the Taig, I have put together a listing of all the accessories one needs with the Taig for doing stem work: (prices as of 8/03) If you prefer, you can download this table here as an Excel file.
This is a list of the accessories necessary to equip a Taig lathe to turn pipe stems. Though I have no firsthand experience with them, I have heard that www.cartertools.com is the best place to purchase this lathe and its accessories. (The prices listed below are from that site.)
Part No. Description Price L1017 Micro Lathe basic unit (factory assembled) $ 170.65 OR K1019 unassembled $ 142.50 1021A Motor 1/4HP 1725rpm 1/2"arbor $ 75.00 1022 Motor mount bracket $ 5.00 1023 Mounting board 12"x18" $ 5.50 OR 1024 8"x24" 1060 4-jaw self-centering chuck $ 66.00 1092 Jacob's chuck 1/16"-3/8" $ 9.25 1095 Tool bit set 6 piece $ 25.20 OR 1097A left hand tool bit $ 4.50 1150 Drilling Tail Stock $ 35.50 1151 Needle Bearing Center $ 13.50 1162 Pulley set for 1/2 arbor (specify: belt 500) $ 22.25 OR (specify belt 350 if using mounting board 1024) Total assembled $ 427.85 Total unassembled using alternative parts $ 379.00