Bending Methods

There are five typical methods of bending in the industry: rolling, incremental bending, hot bending, rotary-draw bending, and induction bending. Each method has its advantages. Some methods are more commonly used in the steel construction industry, while others are more common in the automobile or manufacturing industries. The six most widely used bending processes in the industry are below, listed in order based on prevalence of use in the industry:

• Rotary-Draw/Compression Bending

  is where the structural member is bent by rotating it around a die. The member is clamped into a form and then is drawn through the machine until the bend is formed. This method produces tight radii and is mainly used for complicated bends in the machine and parts industry.

• Rolling (a.k.a. "Pyramid" Rolling) or Cold Bending

  is the typical method of curving steel for construction and is usually the most economical for rolling members with tighter radii. A steel member is placed in a machine and curved between three rolls. Cold bending may also be called "pyramid rolling" because of the three rolls' pyramid arrangement. Bending occurs when the distance between these rolls is manipulated before each successive pass.

• Point Bending or Gag Pressing

  is usually used for cambering and curving to very large radii. Bending is achieved by applying a minimal number of point loads with a hydraulic ram or press at selected points.

• Synchronized Incremental Cold Bending

  is performed by applying pressure in a highly synchronized fashion at several locations on the section. This can result in tight radii with minimal distortion.

• Hot Bending

  is where a structural member is heated directly and then bent. The heat source could be a direct flame or furnace. This application is used extensively in repair. Hot bending is not an induction process, but it does internally heat the material allowing us to bend to extremely tight radii and to meet AESS quality standards.