The metal stamping process has evolved as a technique to punch out coins to the point where almost every industry relies on metal-stamped parts to complete a machine assembly. Even with the difference in sizes and functionality, the common factor that decides the quality of the metal part is its accuracy in the design.
The slightest deviation in the design could render the metal stamping part useless or affect its ability to deliver the desired function in an assembly. Therefore, metal stamping manufacturers need to pay attention to details and ensure the material, the die design, and the tools work well to create the desired metal part that perfectly fits into the machine assembly.
This article discusses vital matters that metal stamping companies must attend to for a successful metal-stamping process.
Problems that need attention during the metal stamping process
Deep Drawing Parts
Deep drawing involves creating hollow parts in a flat blank metal sheet. It can also include using the hollow parts as blanks to change its dimensions, like reducing the diameter and increasing the height. Therefore, for the best metal stamping results, metal stamping companies must look for:
it should be as simple and symmetrical as possible because axisymmetric deep drawing helps in getting a uniform deformation in the circumferential direction, easy die processing, and the best manufacturing performance.
the depth of the drawing part must comply with the material properties of sheet metal parts. Ideally, the depth should be within 0,2 times the diameter. As the depth increases, deep drawing parts have higher chances of tearing. If the design demands high depth, it is only wise to use shallow drawing to avoid tearing.
Metal stamping companies need to ensure proper deep drawing. For this, they need to give attention while choosing the distance from the edge of the hole on the top or flange of the tensile piece to the side wall. Other dimensions that need due attention while the calculation is:
- filet radius of the bottom and side walls
- the wall surface of the deep drawing part
Stretching comes into the metal stamping picture when there is a need to increase the surface area of the blank. Here the tension is used, and there is no inward movement of the blank edge. Ideally, metal stamping companies must stretch the limit to a single time. However, sometimes there may be a need to stretch the metal parts multiple times. In such cases, metal stamping companies must maintain the quality of the metal-stamped parts and keep the traces to a minimum.
Wrinkles on the parts:
Wrinkles are unwanted features that usually appear on the side walls of the metal stamped part due to the difference in gaps on either side wall. The difference is mostly because the metal sheet has a thickness less than the minimum allowable thickness or has eccentricity while installation of the molds.
Scratches and cracks on metal stamping parts
Scratches and cracks not only alter the aesthetics but also make the metal stamped part completely useless. Grinding the scars on the mold and cleaning the metal dust can prevent scratches on the metal part.
To avoid cracks, the main thing to consider is the right choice of material. The metal must have sufficient plasticity to endure the stress during the stamping process. Loosening the blank holder can also help prevent cracks.
Wearing of the die edges and punch:
Metal stamping companies should always look out if the punch and die edges are in good condition. If any signs of wear are found, the process must be stopped, as continuing could increase the risk of expanding the wear degree and accelerate the wearing process. Wearing of die edges and punch, if left unchecked could incur losses as it will fail to produce high-quality metal stamped parts.
Metal stamping companies should always have an eye for the above-mentioned points to ensure the quality of metal-stamped parts. Strict inspection before installation and during the process can also help find errors in time and save the companies from losses.