What are the causes of burrs in metal stamping parts

What are the causes of burrs in metal stamping parts
In the processing of metal stamping parts, sometimes it is found that the stamping parts have some burrs of different sizes, which have a certain impact on product quality. So what are the causes of burrs in metal stamping parts?
1. Blunt cutting edge. Burrs can be produced when the cutting edge becomes dull or gnawed. The factors that affect the cutting edge dullness are:
1. The material and surface treatment of the convex and concave molds are poor, and the wear resistance is poor;
2. The die structure is poor and the rigidity is poor, causing gnawing injuries;
3. If it is not lubricated in time during operation, it will wear quickly;
4. Failure to sharpen the edge in time.
Metal stamping parts
2. Gap. If the blanking gap is too large, too small or uneven, burrs can be produced. The following factors affect the gap that is too large, too small or uneven:
1. Mold manufacturing errors, die parts processing that do not meet the drawings, and the bottom plate parallelism is not good, etc.;
2. Mold assembly errors, large gaps in the guiding part, different assembly of convex and concave molds, etc.;
3. The precision of the press is poor. For example, the gap between the guide rails of the press is too large, the bottom surface of the slider and the surface of the worktable are not parallel, or the stroke of the slider is not perpendicular to the press table, and the rigidity of the worktable is poor. Deflection during cutting can cause the gap to change;
4. Installation error, such as the surface of the upper and lower bottom plates of the punching die is not cleaned during installation or the method of fastening the upper die of the large punching die is improper, the upper and lower die of the punching die are installed out of concentricity (especially the die without guide pillar) and the working part is tilted;
5. The structure of the die is unreasonable, the rigidity of the die and the working part is not enough, the punching force is unbalanced, etc.;
6. The steel plate has large curvature and uneven steel plate.
Metal stamping parts
3. Improper blanking state
For example, if the blank (including the intermediate part) is not in contact with the punch or die, when the trimming and punching with an improperly positioned relative height, the height of the part will be lower than the relative height of the positioning, and the shape of the part during the punching process Burrs are generated due to incompliance with the shape of the cutting edge.
Metal stamping parts
Fourth, the workmanship of the parts is poor
Complicated shapes with convex or concave sharp corners are prone to burrs due to rapid wear.
Metal stamping parts
Five, the material does not meet the craft regulations
The thickness of the material is seriously out of tolerance or the wrong material (such as the wrong steel grade) causes the relative gap to be unreasonable and causes the part to produce burrs.
The above content is about the causes of burrs in metal stamping parts, I believe everyone has already understood. The burrs of metal stamping parts are usually produced in sheet metal blanking. Generally speaking, it is difficult to avoid. By improving the processability of the parts and improving the stamping conditions, the burrs can be avoided or reduced.