Progressive die drawing, or stamping, is a forming process that utilizes a series of stamping stations to perform simultaneous operations on sheet metal. The final metal workpiece is developed as the strip of metal is processed through the stamping die.
The progressive die stamping process characteristics include:
- The utilization of multiple cutting and/or forming operations simultaneously,
- Excellent suitability to produce small workpieces at a rapid rate,
- The necessity to invest in expensive die sets,
- The ability to save time and money by combining forming operations,
- The capability to maintain close tolerances, depending on the tools.
The illustration that follows provides a two-dimensional look at a typical progressive die metal drawing process in two steps – one open die and one closed die.
As the metal strip is moved through the drawing process, it is exposed to a series of progressive die stations, each one changing the metal configuration left on the metal by the previous station. Therefore, the metal workpiece is created in a series of stamping stages.
The illustration above depicts the metal strip moving to the next workstation before the die closes.
The second illustration shows a closed die with the finished component workpiece falling out of the die on the lower right hand side.
The overview on the top of the second illustration shows a "birds eye" view of the metal strip as it is going through the dies.
During the drawing operation, punches in the die can perform cutting, forming, and drawing operations to produce the needed component.
Normally, this process is limited to shallow draw stamping. A related process, deep draw stamping, allows the metal to be drawn more deeply, often to a ratio of 7 or 8 to 1.
Tooling in progressive die drawing is complex and relatively expensive.
Common materials progressively drawn include:
- Aluminum
- Brass
- Cold rolled steel commercial steel
- Cold rolled draw steel
- Cold rolled stainless steel
