To connect a branch to a length of pipe B, Fig. 257, drill a hole about 3/8-inch in diameter in the pipe. Beginning with the small collar lifter, lift the edges of the hole carefully and evenly all around by strokes of the hammer on the under side of the lifter. When the hole is increased an inch or more in diameter, the larger lifter may be used. Care must be taken not to crack the metal by excessive expanding without annealing, nor by too much hammering at one place. When a collar is raised as shown at C, the edge is flared and a cup joint is formed for brazing.

Another type of branch joint may be made by cutting a hole in the pipe nearly the size of the desired outlet, lifting the edge as a slight collar, and placing over the outside of this collar the end of the branch. This end is suitably flared to lie snugly against the outer surface of the pipe which it joins, forming a saddle flange which is brazed to the pipe.

A hole in a copper pipe may be stopped by brazing on a flush patch, which lies flush with the surface of the pipe, or by brazing on an exposed patch, which overlaps the outer surface of the pipe.