Common black iron pipe is steel. The steel is rolled into a tube and then welded. You can usually see and feel the seam on the inside of the pipe.
Short pieces of pipe that are threaded on both ends are called nipples. They are often painted black with paint, black tar/asphalt, or something that seems like raw steel coated in graphite. I prefer the raw steel and tar/asphalt. It can be difficult to tell the difference between paint and tar/asphalt.
Special couplers used to finish and pull together a closed section of pipe are called Left/Right Nipple And Coupling Sets.
The black-iron pipe fittings are often referred to as black iron but are usually make of malleable iron (not quite steel, but better than iron). Galvanized is made from malleable iron that has been dipped in zinc to help prevent rust. Avoid galvanized pipe and fittings. Avoid welding galvanized pieces as they will release poisonous fumes.
Common pipe wall thickness is referred to as schedule 40. Heavy duty, high pressure pipe is referred to as schedule 80. There are many other schedules and classes of pipe.
My favorite brand of black-iron fittings is Anvil, which are made in the USA. My second favorite brand is TSP (Tri Sinar Purnama), which are made in Indonesia. SCI is another common US-made brand. Their fittings are fine, but a bit ugly. They have a nice web site, which is easy to browse. My least favorite brand is Mueller, which is made in China. Unfortunately, most consumer retail stores seems to be moving to Mueller. My main complaint is that their fittings are ugly, both in terms of their finish and the haphazard way to cast marks and codes into the iron with no sense of style or craftsmanship.
Anvil International http://www.anvilintl.com/product/pipefittings.aspx
TSP (Tri Sinar Purnama) http://www.trisip.com
SCI (Smith-Cooper International) http://www.smithcooper.com/cat.php?g=2757
Mueller Industries http://www.muellerindustries.com/
lamp, small table
Use 1/8" steel NPT fittings.
- 2 - tee fittings Anvil 8700120309, Malleable Iron Pipe Fitting, Tee, 1/8" NPT Female, Black Finish
- 3 - 90 degree elbow fittings Anvil 8700123550, Malleable Iron Pipe Fitting, 90 Degree Elbow, 1/8" NPT Female, Black Finish
- 3 - plug fittings
- 3 - 3" nipples Anvil 8700136255, Steel Pipe Fitting, Nipple, 1/8" NPT Male x 3" Length, Black Finish
- 1 - 1-1/2" nipple Anvil 8700136107, Steel Pipe Fitting, Nipple, 1/8" NPT Male x 1-1/2" Length, Black Finish
- 1 - 12" nipple Anvil 8700136701, Steel Pipe Fitting, Nipple, 1/8" NPT Male x 12" Length, Black Finish