The stamp of the type of the press, the tooling must be made to produce a part to a specific configuration.
Although there are other specialty stamping processes used in industry such as hydro forming, multi-slide stamping, and transfer press stamping, our focus here is on the two most commonly used in industry, progressive die stamping as well as short run or small lot stamping .
Progressive Die stamping - As the name implies a progressive die performing operations on a part as the metal progresses or moves through stations in a die. Each station in a progressive die performs a unique operation on the strip of material. In a part regardless of how many operations or stations are in the die. Material is typically feed through a progressive die in coil form and once the press is started the operation does not require much operator interface.
Short run stamping - Short run stamping differs from progressive die stamping in the method in which the tooling is constructed. The tools are engineered to fit into standard holders eliminate the need for a stand alone die set for each part. Short run stamping companies maintain an inventory The most typical punching sizes and form tools. In many cases the only unique tooling produced is the banking die. Material is sheared to width and then hand fed through the blanking tool cutting the part out. Subsequent operations such as forming are performed at another press With the parts being placed into and removed from the tools by hand. Because of the simplicity of the tooling scenario initial cost and lead time is generally a fraction of building a progressive die.
Metal Stamping Parts design guidelines - The guidelines listed below will work for either short run or progressive die stampings. In most instances progressive die stampings can be held to tighter tolerances than listed below with the exception of material thickness tolerance.
Material thicknessness Tolerance - The chart below lists standard tolerance for cold rolled coil and sheet steel. Tighter tolerance can be achieved through secondary rolling although this adds to cost, lead time and results in larger minimum material buys.