Various manufacturing processes require the use of precision metal-stamped products made from slit coil steel, copper, and brass, among other materials. These products are manufactured using power press stamping machines specifically built to produce parts from coiled metal or another similar material.
There is more than one type of stamping machine. The first is the progressive die stamping machine, which allows operations on a piece of metal until a final component is produced. This type of machine combines an automatic feeding system with punching, coining, bending, and other processes for modifying metal raw material and turning it into finished products.
Another type of stamping machine is four-slide/multi-slide stamping machine, which makes possible the production of shapes and bends of varying complexities. This type of machine is used in the mass production of stamped components made from slit coil or wire stock.
Progressive Die Stamping
Progressive die stamping machines use a vertical motion when processing a metal strip. In progressive die stamping, a slit coil metal is fed through a series of stamping stations, each performing a specific operation. The strip begins at the first station, where the die makes the intended cut, bend, or punch. The workpeice then moves to the next station, where the next stamping function is performed. This process continues until the final product is complete and can involve a single step or dozens of steps, based on how complex the design is.
Since each part is attached to the metal strip throughout the formation process, a pilot must be placed into pre-pierced holes to hold the metal in place as it moves through the process. The SMED (Single Minute Exchange of Dies) principles, pioneered by Shigeo Shingo, can be applied to this process. SMED allows dies to be changed quickly and easily to accommodate different designs and is standard practice at Keats.
Progressive die stamping has several advantages over other stamping methods, such as four-slide or multi-slide machines.
- Less time to set up: Progressive die stamping takes 38% less time to set up than multi-slide stamping. This allows producers to generate smaller lot sizes and make manufacturing scheduling more flexible to produce what the client wants when they need it. It also reduces the labor involved in the production of parts.
- Repeatability: The machines provide excellent repeatability with tight tolerances. They can generate large quantities of parts without compromising quality.
- High accuracy: Because each station performs a different operation, progressive die stamping is highly efficient and can be used to produce large quantities of parts with a high degree of accuracy.
- Generic Tooling: Because of the simple nature of the forming process, using only vertical pressure, it is possible to move tooling from one supplier to another without the need for a major retrofit. Generally if a press machine of the same tonnage and bed size is available a tool build to run on that bed size and tonnage will be able to run in a different press.