Tooling design begins with the part you want to make. Before that part can move into production, the tooling has to be designed around its shape and the way it will be compacted.
That can make seemingly small design decisions worth a closer look. A tight tolerance may add complexity. The shape of a hole could make the tooling simpler or harder to build. In some cases, a small adjustment to the part can make a noticeable difference in the manufacturing process.
This is why tooling is worth thinking about early. Before getting into the design decisions that can affect a project, it helps to understand the role powder metal tooling plays during compaction.
Powder metal tooling gives a part its shape during compaction. Metal powder is fed into a die cavity and compacted under high pressure by the punches, creating a “green” part that is later sintered.
The tooling setup is designed specifically for the component being produced:
A feature that looks simple on a drawing may require a different approach once it is translated into tooling.
Once a part moves into tooling review, some features require more engineering attention than others. Catching those considerations early can reduce revisions before tooling is built.
Certain geometries can make tooling design more involved. Specialized gear profiles, for example, may require additional engineering evaluation before the tooling approach can be finalized.
A component designed with kidney-shaped lightening holes may be evaluated for alternative feature shapes. Changing those holes to round profiles can reduce tooling complexity and lower tooling costs without affecting part performance.
Tighter tolerances leave less room for variation during manufacturing. When those requirements go beyond what the part needs to function, they can add unnecessary complexity to the tooling and development process.
Different powder metal materials behave differently during processing. Some materials, particularly stainless steel grades, can experience greater dimensional change and may require additional design analysis before production begins.
Production volume is part of the tooling conversation, but higher quantities don’t necessarily mean the basic tooling design has to change.
Atlas notes that the fundamental tooling design remains fairly consistent across a wide range of production volumes. Once annual demand reaches higher levels, typically above 100,000 parts, additional tooling sets may be needed to support production efficiency.
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Production Consideration |
What It Means for Tooling |
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Lower to moderate volumes |
One tooling set may be enough to support production requirements. |
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Higher volumes |
Additional or backup tooling sets may be needed to keep production moving. |
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Annual usage |
Expected demand helps determine the tooling strategy during the quoting process. |
For higher-volume programs, backup tooling gives the manufacturer another set to work with as production continues. That additional tooling becomes part of the overall investment when production demands call for it.
Before a tooling cost or lead time can be estimated, the manufacturer needs enough information to evaluate the part and how it will move into production.
That review starts with four pieces of information:
Once that information is available, the manufacturer can look at how the part translates to powder metallurgy and identify any design changes needed before tooling is built.
Some parts take longer to work through than others. A complex geometry may need a closer look before the tooling approach is settled. Tight tolerances can also require more time during the design process.
The information provided at the start matters too. You’ll need:
This information gives the manufacturer a better basis for estimating tooling cost and lead time.
A finished drawing provides the starting point for tooling review, but it does not mean every feature must remain exactly as designed. Evaluating a component before tooling is built gives engineers an opportunity to identify design modifications that may improve manufacturability, simplify tooling, or reduce overall production costs.
Consider a design that consists of two separate components requiring individual manufacturing operations and then assembly. In some cases, those components can be consolidated into a single powder metal part. Eliminating the assembly step can streamline production, reduce processing costs, and simplify the overall manufacturing workflow.
The same approach can be applied to individual part features. Looking at how a design translates into tooling gives engineers another chance to simplify individual part features while maintaining the intended function of the part.
Good tooling design starts well before production begins. The decisions made during part design can influence tooling complexity and how efficiently a project moves toward production.
Taking the time to review the design early gives engineers a chance to make changes while there is still flexibility. A small adjustment to a feature or tolerance could simplify the tooling approach and help set clearer expectations for cost and lead time.
There’s plenty more to consider before a powder metal part reaches production. Get practical tips you can bring to your next project with the PM Design Guide.