Swaging permits two pieces of soft copper tubing of the same diameter to be joined together without the use of fittings

as shown in Fig. 2-17.

The process of swaging copper tubing is often used as it is more convenient to solder one joint than to make two joints when using couplings.

The length of engagement of the two pieces of tubing is important. A general rule is to make the length of engagement equal to the outside diameter (OD) of the tubing.

There are two types of swaging tools available: the punch type and the screw type. In both cases, different sizes are available for use with the various sizes of copper tubing. The screw-type swaging tool is used in the same manner as the flaring tool.

When using the punch type swaging tool, the copper tubing is inserted into the correct hole size in the anvil block and then a corresponding punch is inserted into the copper tubing and hammered down until the punch has entered the tubing the desired

distance. Fig. 2-18 shows a punch type swaging tool.

Many prefer to use streamlined fittings when joining two pieces of tubing of the same diameter as it saves the time required to swage the one tube.