Carbon Sheet Metal CNC Machine for Steel Automatic Hydraulic Press Brake

Bend Deduction and K-Factor are material-dependent. The most accurate method is practical testing: make a few test bends with the same tools and material, measure the final dimensions, and back-calculate the accurate value. Many modern press brake controllers have built-in material libraries that provide estimates as a starting point.

Tooling selection depends on material type, thickness, desired bend angle, and inside radius (R). A general rule of thumb is: the die V-opening width is typically 6 to 12 times the material thickness (T) (e.g., for 3mm steel, a 20mm or 25mm V-die is common). Thicker materials or larger radii require wider V-openings.

This is one of the most common issues. Potential causes include: Material variation: Hardness can differ between batches. Tooling wear or misalignment: Check if punches and dies are parallel and aligned. Inconsistent bending speed: Too fast or too slow can affect springback. Machine accuracy: Check if the Deflection Compensation system (e.g., servo-hydraulic compensation or wedge compensation) is working correctly and properly set up.

This is caused by the elastic deflection (bending) of the ram and bed under load. You need to activate or adjust the machine's deflection compensation system. For older machines without compensation, manual compensation can be achieved by crowning the bed or using a crowned die.

Springback cannot be eliminated entirely, but can be controlled by: Overbending: Program a smaller angle than required to compensate for springback. Using a sharper punch: Reduce the punch tip radius (R). Increasing pressure: Use coining mode, but it requires tremendous force. Using a smaller V-die: This increases stretching, reducing springback.