The cutting and threading of steam and gas pipes is done to a considerable extent by hand appliances, but the best results are obtained by a machine which cuts and threads a pipe while holding it rigidly in exact position. These machines are hand or power driven, or may be driven by hand and power.

Pipe cutting and threading may be done accurately in a lathe, provided the pipe is not too long for the lathe. Pipe threading by means of hand appliances does not give satisfactory results when many short lengths of pipe are to be joined in a more or less intricate system, because hand appliances cannot usually cut a thread so that a pipe will turn on its axis while screwing it into place.

Fig. 204. - Pipe-Cutting and Threading Machine.

Fig. 204 shows a small machine which grips a piece of pipe in a chuck C and revolves it in contact with a cutting tool at the right of the machine. The die head D also carries the adjustable thread chasers which thread the end of the pipe.