Cracking of metal stamping parts

2022.09.26 | Technical Knowledge
Precision Metal Stamping Parts

During the processing of metal stamping parts, it needs to go through many technological processes. At the same time, if there is a slight carelessness in the operation process, it is easy to cause the metal stamping parts to crack, tear, and other undesirable phenomena, affecting the normal use of the products.

Reasons for cracking

  1. Excessive local tensile stress: due to excessive local tensile stress during processing, metal stamping parts are subject to internal stress, external impact, etc., resulting in local large bulge deformation and cracking. Hardware stamping die processing.
  2. The implementation of forming process parameters is not in place: during the forming process of the parts, the process requires that the die, the pressing core, and the parts of both need to closely fit together. When the sliding block of the machine tool slides, the plastic deformation of the sheet metal is pressed to achieve the forming. The processing technicians fail to timely adjust the machine tool pressure at this stage according to the process requirements. The work is unstable, causing the stamping parts to crack.
  3. Defects in the design of flanging forming die: the die is shared by the left / right parts of the first mock examination and two cavities. Because this process contains not only flanging but also shape forming, in addition to the special and complex parts, the narrow bending surface, and the forming requirements of the die core are inconsistent with the forming surface, and the die structure conditions lead to large forming stroke, small pressing area, and cracking.

Methods to prevent cracking of metal stampings

  1. Drawing process of metal stamping parts: in the drawing direction, the contact area between the punch and the blank shall be as large as possible, and the reasonable shape of the blank holder surface and the blank holder force shall make the resistance of each part of the blank holder surface uniform and appropriate, reduce the drawing depth, open process holes, and process cuts.
  2. Structural design of metal stamping parts: in the design, the radius Z of each fillet should be larger, the actual depth of the curved surface shape in the drawing direction should be shallow, the depth should be uniform, the shape should be as simple as possible and the change should be as gentle as possible.
  3. Die design of metal stamping parts: reasonable drawing rib design, large die fillet, reasonable clearance between a male die and female die, and other measures can be taken. Metal stampings.

During the processing of metal stamping parts, there will be many faults and defects such as cracks, which require reasonable design and careful operation by the staff of the processing factory to prevent and reduce the occurrence of bad metal stamping parts and improve the product quality.

Video of Quality Inspection of Stamping Parts: Automobile Transmission Bracket

Further reading: Springback of Metal Stamping Parts Solutions


Feng-Yu is a China custom metal stamping manufacturer that was founded in 1971, based on our mastery of precision hardware processing technology and nearly 50 years of experience. Hardware processing provides key components for many industrial equipment and products, such as processing hardware stamping parts, injection molding parts, automotive stamping parts, precision hardware stamping parts, medical devices stamping, and other products. Our company provides a one-stop service process from drawing receiving to sample delivery, with stable quality and commitment, please contact us.

If you have any needs for stamping parts or are interested in our metal stamping services, welcome to contact us.