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What is the reason for the high scrap rate of metal stamping parts?

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  1. The raw materials do not meet the standard.

Raw material is the first guarantee for processing qualified stamping parts. If the raw material hardness and surface quality cannot meet the requirements, the scrap rate of stamping parts will be too high. Especially for some stamping parts with large deformation, if the raw materials are not qualified, cracks and damage will occur. Therefore, when purchasing raw materials, we cannot be greedy for cheap, but look for reliable and regular raw material business.

Second, the die is not installed as required.

The installation of the molding die does not meet the requirements of the specification, resulting in poor cooperation between the upper die and the lower die in the die, resulting in a high rejection rate. Stamping die is the basis of stamping parts processing. Installation is important if there is no problem with the mold. Don’t think that the installation of stamping die is very simple, even a small error may cause the production of stamping parts to be scrapped. The determination of the concentricity, clearance and flatness of the upper and lower dies has an important influence on the installation of the punching die.

Third, mold wear.

Long-term use of stamping dies, worn or loose parts can also cause product scrap. Many stamping plants do not carry out routine inspection and maintenance after installing production molds. Only in the case of relatively large burrs, the mold can be removed and the blade can be simply sharpened. We know that mold wear is not only the wear of the blades, but also causes the wear of some mold parts with use. After such parts are worn, it will affect the accuracy of the entire mold.

4. Illegal activities of workers.

When operating the press, the staff cannot follow the instructions, otherwise the paper will be fed incorrectly.

5. Wrong positioning device.

Due to the inaccuracy of the mold positioning device during the feeding process, it will cause improper coordination of each process, and even cause waste.

For metal stamping parts, since each stamping part requires different stamping parts, there must be specific reasons and specific analysis methods. If the scrap rate of stamping parts is too high, you might as well find out the reasons from these five aspects.

However, the precision requirements of metal punching and drawing parts in the processing industry are often very high, and the requirements for suppliers are also getting higher and higher. However, not all metal stamping factories meet the high precision requirements. Problems that should be paid attention to in the production of die castings:

1. Regularly check the punch, punch and punch mounting seat to ensure the same accuracy of the upper and lower turntables.

2. Metal stamping parts should be strictly cleaned before installation and use. On stamping parts, carefully check that the guide sleeve and die are well lubricated.

3. In order to ensure the drawing and pressing of the parts, the die spring should be replaced regularly to prevent the fatigue damage of the spring and affect the use of the drawing and pressing parts.

4. When installing the die, the stamper should use metal working tools to prevent damage to the stamping parts due to impact and extrusion during the installation process.

5. After the punch and punch edges of stamping parts are worn, they should be stopped and polished immediately. Conversely, edge wear will expand rapidly, die wear will accelerate, and stamping quality and die life will be shortened.

6. According to the installation steps of the die, install the punch and punch on a turntable to ensure that the punch is in the same direction. In particular, the hole punch should be installed strictly according to the orientation to prevent wrong installation and reverse installation.

6. How to calculate the scrap rate of stamping parts

1. The calculation method is as follows:

a. Calculated by weight Casting scrap rate = (casting scrap output / total casting output) X100%

b. Calculated by quantity Casting scrap rate = (number of scrap castings / total number of castings) X100%

2. Scrap Rate, Scrap Factor

The probability that a component will become defective while it is being used to make the parent. The same component may have different scrap rates when used to produce different parent items, so the scrap rate is defined in the bill of materials. When MRP uses the BOM to expand the POR (planned order issuance) of a material to calculate the GR of its components, it will be divided by (1-scrap rate) to expand the GR (total demand) of the components.

The above is the relevant content of the high scrap rate of metal stamping parts and the scrap rate of stamping parts. Qualified products should be strictly regulated. Only by ensuring product quality, stamping parts manufacturers can stabilize the source of customers and go further. Hope the above content is helpful to readers.

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