Because of its exceptional formability, copper can be formed as desired at the job site. Copper tube, properly bent, will not collapse on the outside of the bend and will not buckle on the inside of the bend. Tests demonstrate that the bursting strength of a bent copper tube can actually be greater than it was before bending.

Because copper is readily formed, expansion loops and other bends necessary in an assembly are quickly and simply made if the proper method and equipment are used. Simple hand tools employing mandrels, dies, forms and fillers, or power-operated bending machines can be used.

Both annealed tube and hard drawn tube can be bent with the appropriate hand benders. The proper size of bender for each size tube must be used. For a guide to typical bend radii, see Table 13.

The procedure for bending copper tube with a lever-type hand bender is illustrated in Figure 9 below.

Figure 9. Bending Using a Lever-Type Hand Bender (tool shown is appropriate for use with annealed tube only)

(A) With the handles at 180 degrees and the tube-holding clip raised out of the way, insert the tube in the forming-wheel groove.
(B) Place the tube-holding clip over the tube and bring the handle into an approximately right angle position, engaging the forming shoe over the tube. The zero mark on the forming wheel should then be even with the front edge of the forming shoe.
(C) Bend by pulling the handles toward each other in a smooth, continuous motion. The desired angle of the bend will be indicated by the calibrations on the forming wheel.
(D) Remove the bent tube by pivoting the handle to a right angle with the tube, disengaging the forming shoe. Then release the tube-holding clip.

The tool illustrated is just one of many available to the industry. Of course, if the manufacturer of the tube bender has special instructions regarding his product, such instructions should be followed.