Some degree of distortion will occur as tube steel reacts to the bending process. It is critical to find a bender that can minimize this distortion. Albina is the BEST choice!
Figure 2 depicts a cross-section, in an intentionally exaggerated visual, how hollow structural steel (tube steel) typically deforms during a roll bending process without internal support. Figure 1 depicts a piece of unbent material. Figure 2 depicts a piece of bent material.
Tube steel reacts to bending processes by collapsing inward as a result of compression across the bend section (B) and the inside face (A) of the material.
Severity of deformation is increased when using thinner wall material and/or bending to tighter radii. Deformation of the tube faces is also dependent on material sizes and direction of rolling (i.e. Hard-Way vs. Easy-Way) when bending rectangular tube steel.
Face (A) will deform more significantly when bending rectangular material the Easy-Way vs. the Hard-Way. The reverse is true for face (B). Face (C) will always deform the least regardless of bend direction. In extreme cases, faces (A) and (B) may not only collapse inward, but can result in alternating inward and outward collapsing as large wrinkles throughout the bend section.