Supported by advancements in information technology, the machine tool industry—and specifically our pipe-bending machine sector—has undergone significant transformation in recent years. Information technology facilitates the development of CNC capabilities in pipe-bending products. When evaluating a high-quality pipe-bending machine, the primary consideration is economic viability rather than merely the ability to execute a complex bend. While even the most challenging bends are technically feasible, the associated production costs can be prohibitive; therefore, careful planning regarding the tubing material is essential for efficient processing.

Regarding tooling for pipe-bending machines, a distinction is often made between mandrel bending and mandrel-less bending. Mandrel-less bending is the simpler process and is commonly used for carbon steel pipes, particularly galvanized pipes with large bending radii and thick walls. Our double-head hydraulic pipe-bending machines utilize this method, which offers lower tooling costs and reduced technical complexity. Conversely, mandrel bending presents greater technical challenges. This is especially true when using specialized processing machinery that incorporates auxiliary tooling—such as mandrels and anti-wrinkle dies—as the setup and adjustment of these tools are significantly more complex.

For solid bars of the same diameter as the pipe, a proper fit with the anti-wrinkle plate can be achieved. When the bar is controlled by the clamp die, it gently pushes the anti-wrinkle plate to the foremost position, thereby protecting the plate's mounting fixture. The flat end of the anti-wrinkle plate can be retracted from the pressure die to minimize tensile stress. To verify the angle, a straight edge is aligned with the center of the clamp die groove, extending to the rear of the anti-wrinkle plate; this horizontal edge should be positioned as close as possible to the point of tangency. Anti-wrinkle plates made of Ampco bronze help reduce tensile stress and prevent scoring. Plates made from 4130 steel have proven highly successful, exhibiting significantly less wear than those made of low-carbon steel or Ampco bronze. Only a small amount of high-quality lubricant is required; excessive oil can lead to wrinkling.

Situations that may cause pipe breakage during bending on fully automatic pipe-bending machines:

A. Insufficient flexibility or elongation of the mandrel.