Holden has extensive knowledge, capability and capacity in the forming and bending of complex sections in both aluminium and other materials.

This range of expertise incorporates stretch forming, flow forming and roll forming capable of meeting a wide variety of applications for the controlled forming and bending for a wide range of applications and volume requirements including prototype and economic small batch manufacture

Stretch Forming

Stretch Forming is the most accurate, repeatable and fastest of the forming processes. There are a number of features to the process:

• It can be applied to a wide range of sections up to a cross section of 300x300mm making the process very flexible to a wide range of applications.
  
  
• In addition to bending in 2 planes Holden have developed the capability and equipment for 3 plane bending to create spiral type forms at lower cost than fabrication
  
  
• For symmetrical parts left and right hand forms can be produced in a single forming operation reducing costs
  
  
• The control parameters can be set to incorporate compression bending to give tighter corner radii – overcoming the limitations of material yield strength.

Flow Forming

Flow forming has the advantage of lower set up costs than stretch forming but is limited to single plane forming. Features of flow forming include

• Enhanced equipment capability allows forming of large cross sections up to 260mm in high and 250 in depth, such as bumpers and monorail lift parts
  
  
• Suitable for forming hollow sections by the use of floating mandrels or other fillers for irregular internal cross sections
  
  
• Maximum bend radii up to 180 degrees
  
  
• Tooling development has enabled minimum bend radii to be reduced for 3:1 to 1:1 allowing tighter bends

Roll Forming

Roll forming is used for shallow form single swept parts. Features include

• Minimal tooling costs with common tooling used for multiple radii, parabolic curves and edge forming on the same part. For simple profiles such as rectangles, and square section standard tooling is used
  
  
• Investment in CNC equipment reduces set up costs and extends range of capability over the original 3 roll machines to include three dimensional shapes
  
  
• Reduced sensitivity to material batch variations through programme modifications rather than hard tool recuts

Ideal for low to medium volumes including prototype and development requirements.

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