The Art and Science of CNC Machining: Bending Metal with Simon)

  • Time:
  • Click:13
  • source:FANYA CNC Machining


CNC machining has revolutionized the manufacturing industry by streamlining production processes, enhancing precision, and enabling complex designs to be transformed into reality. Within this realm, one essential aspect is the bending of metal. This article delves into the intricacies of CNC machining, focusing on the art and science behind the bending of metals.

Understanding CNC Machining:

Computer Numerical Control (CNC) machining involves using software-controlled machines to fabricate parts from various materials, including metal, wood, plastic, and more. These machines precisely follow a pre-programmed set of instructions to perform precise movements and cuts. While CNC machining encompasses numerous techniques like milling, turning, drilling, and plasma cutting, our focus here will be specifically on bending metal parts.

The Process of Bending Metal:

Bending metal within CNC machining refers to the process of manipulating a piece of metal, typically sheet or tube, to form specific shapes or angles without breaking it. Notably, there are different methods employed for various types of metals and applications. Let's take a closer look at some common techniques:

1. Press Brake:
One widely used method for bending sheet metal is the press brake technique. It involves placing the metal between two dies, with one acting as a stationary bed and the other serving as a moveable punch. High pressure is then applied that gradually bends the metal into the desired shape. The accuracy and quality achieved through this method largely depend on the skill and expertise of the operator.

2. Tube Bending:
When it comes to bending tubes, CNC mandrel tube bending is often employed. In this technique, a flexible mandrel is inserted inside the tube to prevent collapsing during bending. The tube is then carefully bent around a forming die while being supported by other components. Precise control over factors such as wall thickness, radius, and angle is critical to producing accurate tube bends.

Advanced Techniques for Precise Bending:

1. Three-Roll Bending:
This technique involves the use of three rollers – two on one side and another on the opposite side – to bend a metal cylinder or tube into various shapes. The rolls move in unison, applying force and creating curvature along the length of the material. Three-roll bending is often employed for large structures where precise circular bends are required, such as pipes and drums.

2. Rotary Draw Bending:
Rotary draw bending is commonly utilized when tight radius bends are necessary. This method employs a stationary counterbend die, clamp die, pressure die, and follower roll that work together to shape the metal around a central bend die. It ensures excellent control over wall thinning, resulting in outstanding accuracy and repeatability.

Challenges and Benefits of CNC Machining Metal Bending:

While CNC machining offers immense benefits, including reduced production time, enhanced precision, and elevated product quality, there are unique challenges associated with metal bending:

1. Material Selection: Different metals exhibit varied characteristics during the bending process, such as elasticity, ductility, and springback tendencies. Understanding these properties is crucial to selecting the appropriate metal for specific applications.

2. Tooling Considerations: Determining suitable tooling and dies is essential for achieving desired accuracy and minimizing defects like wrinkling, tearing, or excessive stretching during metal bending operations.


CNC machining has transformed metal fabrication by introducing sophisticated techniques for bending to produce intricate designs and functional components accurately. From press brake methods to advanced processes like rotary draw bending and three-roll bending, each approach provides unique capabilities while maintaining strict tolerances, even for complex geometries. By combining technological expertise with skillful craftsmanship, CNC machinists can accomplish remarkable results, allowing industries to leverage the full potential of metal bending for diverse applications across sectors. CNC Milling CNC Machining