Heads with the center on the same line are called concentric heads. The usual forming process is reducing pressing, expanding pressing or reducing and expanding pressing, and stamping can also be used for reducing pipe of some specifications.

The size head (reducing pipe) is a pipe fitting used for pipe diameters. The usual forming process is reducing pressing, expanding pressing or reducing and expanding pressing, and stamping can also be used for reducing pipe of some specifications.

A. Reducing/expanding forming

The shrinking forming process of the large and small heads is to put the tube blank with the same diameter as the large and small heads into the forming die, and make the metal move along the die cavity and shrink to form by pressing along the axial direction of the tube blank. According to the diameter of reducing pipe, it can be divided into one pressing forming or multiple pressing forming.

B. Stamping forming

In addition to the use of steel tubes as raw materials for the production of large and small heads, some specifications of the size of the head can also be produced with steel sheet stamping forming process. The shape of the punch used for drawing refers to the design of the size of the inner surface of the head, and the die is used to press and draw the steel sheet after blanking.