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12 major problems with sheet metal bend molding technology
- 2020-09-17 11:06:53 -

Sheet metal processing is the hub technology that sheet metal technical staff need to grasp, and it is also an important process for sheet metal products to form. Sheet metal processing is including the traditional cutting material, cutting processing, bend molding and other methods and process parameters, in which bend molding process will often encounter some problems, below we look at what problems and how to solve them.

304 stainless steel 5mm bending parts

Question 1: The bend edge is not straight, the size is not stable.


1, the design process does not arrange the line or pre-bend.

2, the material pressure is not enough.

3, convex die fillet wear asymmetry or bend force is not uniform.

4, the height size is too small.


1, design line or pre-bending process.

2, increase the pressure.

3, convex die gap is uniform, rounded polishing.

4, the height size can not be less than the minimum limit size.

Question 2: Scratch on the outer surface after the work piece bends.


1, the surface of raw materials is not smooth.

2, convex mold bending radius is too small.

3, bending gap is too small.


1, improve the finish of the convex mold.

2, increase the bending radius of the convex mold.

3, adjust the bending gap.

Question 3: There are cracks in the bending angle.


1, bending the inner radius is too small.

2, the material pattern and bending line parallel.

3, rough burr one face out.

4, metal plasticity is poor.


1, increase the bending radius of the convex mold.

2, change the discharge.

3, burrs changed in the preparation of the inner fillet.

4, de-ignition or the use of soft materials.

Question 4: Bending causes hole deformation.

Cause: The outside of the bending arm is pulled by friction between the concave surface and the outer surface of the part when the elastic pressure bends and the hole is positioned, which deforms the positioning hole.


1, the use of shape bending.

2, increase the pressure of the top plate.

3, add a plaid on the top plate to increase friction to prevent the part from slipping when bending.

Question 5: The curved surface extrusion material becomes thinner.


1, die fillet is too small.

2, convex die gap is too small.


1, increase the radius of the die fillet.

2, correct the convex die gap.

Question 6: The end face of the part is bulging or uneven.


1, when bending, the outer surface of the material is pulled in the direction of the circumference to produce contraction deformation, the inner surface in the direction of the circumference is pressed to produce elongation deformation, so that in the direction of bending the surface of the curve to produce bulging phenomenon.


1, the preparation in the final stage of stamping convex mold should have sufficient pressure.

2, make and make the outer fillet of the part corresponding to the concave fillet radius.

3, increase the process to improve.

Question 7: The bottom of the concave part is uneven.


1, the material itself is not flat.

2, the top plate and material contact area is small or the top material force is not enough.

3, concave mold without top material device.


1, leveling materials.

2, adjust the top material device, increase the top material force.

3, increase the top material device or correction.

4, plus plastic process.

Question 8: The two-hole axis of the two sides is misalved after bending.

Cause: The material bounce changes the bending angle so that the center line is moved correctly.


1, increase the correction operation.

2, improve the curved mold structure to reduce material rebound.

Question 9: The accuracy of hole position size cannot be guaranteed after bending.


1, the part unfolded dimensions are not right.

2, material rebound caused.

3, positioning instability.


1, accurate calculation of blank size.

2, increase the correction process or improve the bend molding structure.

3, change the process processing method or increase the process positioning.

Question 10: The curved line is not parallel to the two-hole center online.

Cause: When the bending height is less than the minimum bending limit height, the bending area is exwelling.


1, increase the height size of the bend.

2, improve the bending process.

Problem 11: The width direction is deformed after bending, and the bow deflection appears in the width direction of the bent part.

Cause: Torsion and deflection due to the inebriation and contraction of the width direction of the part.


1, increase the bending pressure.

2, increase the correction process.

3, to ensure that the material pattern and bending direction has a certain angle.

Question 12: The cut-out parts are scratched downwards.

Cause: The int cut makes the two straight edges open to the left and right, and the deflection appears at the bottom of the part.


1, improve the structure of the components.

2, cut to increase the amount of process retention, so that the cut is connected, bent and then the amount of process retention cut.