Metal stamping guides and resources for designers, engineers and metal part buyers. Valuable information for anyone considering metal stampings in their manufacturing process. Start your metal stamping research here. Developed by metal stamping experts.
There are three basic types of metal stamping processes.
1. Stage Tooling
2. Permanent Stage Tooling
3. Progressive Die Tooling (also a type of Permanent Tooling)
A fourth non-stamped type is a Fabricated Part. Useful for very low-volume and prototype applications. No tooling costs but higher machine time and labor costs raise the per part cost. Fabricated Parts are useful in the design stages and often help the metal stamper assist with engineering changes that result in better and lower cost stamped parts. Metal stampers with complete fabrication capabilities, advanced tool design, experienced stamping engineers and complete tool making facilities can collaborate to "design in" cost savings in the final part by assuring the correct stamping methods.
Each has distinct costs and advantages for parts in various situations - including material type, annual volume, design change frequency and run size (related to inventory costs and supply chain considerations).
Fabricated Parts [back to top]
This
is an example of a fabricated part produced using a turret press and formed
using a press brakep>
Machine time is higher due to reduced part throughput.
Fabricated parts are usually produced in low volumes.
Dimensional tolerances are usually not as precise as for stamped parts.
Produced as a combination of Laser cutting, Waterjet, Turret Press and Press Brake forming.
No tooling costs but complicated parts may incur costs for programming laser waterjet and turret systems.
Stage tools consist of dies created for each "stage" of the part's creation. There may be separate tools for for blanking (stamping out the edge dimensions), for forming (bends, draws, etc...) and for piercing (various types of holes and notches). In some cases multiple operations may be combined into one tool making a "compound stage tool".
This
is an example of a compound stage tool.
It will both blank out the part as well as perform a piercing operation on the part.
Stage tools may be used for different parts and for different customers. Metal stampers with large selections of stage tooling in stock are often able to provide parts faster and a lower cost than where custom engineered tooling must be created.
Custom stage tools will incur a engineering charge but in the case of compound tooling this will be partially off-set by reductions in production costs depending on production volume.
Permanent Stage Tooling [back to top]
This type of stage tool is normally mounted in a die set. The tool is designed to run a large quantity of parts before needing any service.
Setup time is reduced but flexibility in using the tool on other parts is also reduced by incorporating it into a die set.
The tolerance and alignment capabilities of this tool type exceed the regular stage tooling because the die set has less opportunity for the tool to change position than with multiple individual machine setups.
Progressive Die Tooling [back to top]
Custom designed and made for a particular part progressive dies are created to minimize manufacturing costs such as labor and in-process part movement from machine to machine. Parts are blanked and formed in a strip with a final step to remove the finished part from the strip. Each stroke of the press advances the in-process material one step to where the next operation is performed by the same die. This process results in higher engineering charges to create the advanced tooling but dramatically reduces the per-piece cost of the finished parts.
Punch holder
Progression strip
Die holder
Typically progressive die tooling makes sense starting at 40,000 parts
annually.
Decisions on the cost/benefit of progressive tooling are based on the following types of questions:
Tool cost can either be capitalized in the case of customer owned or provided tooling or amortized in the piece price of the parts over the expected annual quantity of the part. Due to the lower production costs the piece price, even including the tooling cost, will be lower than other tooling options if production quantities are high enough.
