The reason of fracture and wrinkle in stamping and stretching parts

1: If the die gap is too small, the thickness of the material will be thinner and the elongation force will be too large, which will lead to the fracture of the sheet metal. If the gap is too large, it will cause wrinkles in the stretching process, thus increasing the friction resistance. Furthermore, the tensile parts will also fracture.
2: It’s the poor finish. If the finish is not good, the friction resistance will be increased, and the surface of the sheet metal drawing parts will be damaged or even broken. At the same time, it can also shorten the service life of the mold.
3: The blank holder pressure is not suitable, too large or too small. If the blank holder pressure is too high, the friction resistance between the sheet metal drawing part and the die will be increased and the drawing part will be broken. When the blank holder pressure is too small, the parts will wrinkle and make the surface uneven or even fracture.