No matter how much knowledge you have of bending metal, you may still experience some problems. Here are a number of common issues, the causes and how to prevent them in the future:
Cracks in the Bending Angle
Cracks can be caused by poor metal pliability or having a bending radius that is too small. To improve this for next time, try using softer materials or heating your metal and cooling it slowly so it becomes malleable and increasing the bending radius of the punch.
Bending Angle is Not Straight and the Size is Unstable
This issue can be caused by inadequate material pressure and uneven bending pressure. Also, the convex-concave die fillet may be dissymmetric. By increasing the jacking force and balancing out the clearance in the convex-concave die fillet, you will be able to avoid these problems.
Sometimes the friction between the concave die surface and the outside surface during bending can deform the positioning of the hole. You can prevent this by increasing the pressure of the ejector plate or by adding some hard spot on the ejector plate to increase the friction and stop any sliding.
Uneven Bottom of the Concave Piece
If you are using an ejection device, the force may be insufficient or there may be no need for it at all, which is causing this issue. Also, the material you are using may be uneven itself. Make sure that the ejection device is adjusted to the correct measure of force, or completely removed, and your material is evenly levelled before you start bending.
The Bend Is Not Parallel to the Centre of Two Holes
When the bending height is less than the minimum bending limit height, the curve will expand and therefore become distorted. If you increase the height of either the bending parts or workpiece, you will avoid this distortion.
By applying these solutions and paying attention to detail when you are bending your metal, you should be able to overcome these problems every time.