the most common material is black pipe,threaded. There are other materials that could be used though. Your local rental shop should be able to rent you the threader and die to thread the pipe. Threading oil will be required to keep the die cool and the pipe lubed for proper cutting of threads. A pipe clamp/stand would also be handy. If you have'nt done pipe threading, you should get some local advice from either a friend, gas utility company, rental co., or contractor. Your building inspector department may be able to give some advice also.