A socket former is a hand tool, often used by plumbers, to create a connection between copper pipes or tubes of the same diameter.
The socket former is hammered into a deburred (smoothed) copper tube, causing expansion of the pipe diameter over a small length at the end of the pipe. This allows another pipe to slide inside the expanded section and the joint to be soldered.This type of joint, where the objects are slotted together, with no gap in-between them, is known as a capillary joint.
Socket formers are used in plumbing, for water pipes, to do the job which usually requires actual sockets.
Sockets are small sections of copper tube with a slightly larger diameter to join the two pipes together. It is thought by some that forming a socket by the expansion of pipes does not provide the same standard result as a socket itself.Though the soldering process is the same for both, the socket former is less commonly used because the expansion process can cause the pipes to become weaker.
