For manufacturers who require precision parts with tight tolerances, it can pay to compare the options for manufacturing processes. Although fine blanking may be the best choice for certain parts requiring edges with minimal break, progressive stamping can replicate many of the same edge conditions while performing multiple operations on one progressive die. The result can be higher production volumes and lower costs.
According to Art Hedrick, author of Die Basics 101 at thefabricator.com and owner of Dieology, “Among the many factors to consider when choosing a production method are the production speeds necessary to produce the required quantity within a given time frame; the material consumption needed for each part; the production method cost; preventive maintenance requirements; equipment availability; and the part shape, size, and geometric tolerance specified.”
When evaluating progressive stamping vs. fine blanking, manufacturers should ask these three questions.
- Can slight variances be made to the part’s edge condition without impacting function?
- Are secondary operations required after fine blanking or progressive stamping?
- What is the total cost of fine blanking vs. progressive stamping?
Can slight variances be made to the part’s edge condition without impacting function?
The exact specifications of the part provided by the manufacturer tend to dictate the type of production process used. Fine blanking and metal stamping are evaluated for parts that must maintain robust sidewall features in such applications as gears and levers used in automotive and other industries.
Fine blanking is usually considered for parts requiring specific edge conditions or thicker metal, due to the machinery’s ability to achieve extremely flat surfaces and create sidewall features such as teeth or hooks.
Progressive metal stamping can achieve similar edge conditions to fine blanking, by incorporating pre-blanking, shaving and burnishing into the progressive die, which completes these operations in one press pass.
Often, manufacturers seeking to cut parts costs will look to metal stamping as an option to replace fine blanking. Not all parts that are fine blanked can be converted to a metal stamping, but manufacturers may wish to consider their options by consulting with a metal stamping firm for their engineering expertise and cost estimates. For example, critical-to-function dimensions may not be required on all sides of the part, and slight variances may be tolerated without impairing the part’s function and long-term durability. The metal stamping engineers can provide guidance on whether a fine blanked part might be successfully converted to a progressive stamping, as well as develop prototypes for testing.
Are secondary operations required after fine blanking or progressive stamping?
Although fine blanking manufacturers may offer some progressive tooling operations, such as forms and bends, such capabilities are limited with fine blanking machinery and may require secondary operations in-house or from outside suppliers to complete.
In contrast, progressive stamping can incorporate multiple forming and piercing operations by using a progressive die designed exclusively for the part’s critical dimensions.
Secondary operations that can be accomplished with a progressive die include:
- In-die staking, toxing, riveting
- Coining, countersinks
In progressive stamping, the goal is to achieve repeatability and consistent quality by incorporating as many features in-die as possible, which reduces the variability created when going to secondary operations.
What is the total cost of fine blanking vs. progressing stamping?
In general, fine blanking is more expensive than metal stamping due to longer run times. In addition, any time a part needs to move to a secondary operation, costs increase, as does production time. When asking for an estimate on a fine blanked part vs. a progressive stamped part, each firm should provide costs for all the operations required to produce the part to specifications, whether performed entirely in-house or with one or more external suppliers. If the part design allows, precision metal stamping with a progressive die may save significantly on total part costs over fine blanking.