Design for Cost Reduction: How Design Affects Part Cost

The cost of a metal component begins taking shape long before production. A design for cost reduction strategy looks at where those costs are introduced while there is still time to make changes.

A tolerance that goes beyond what the application requires can introduce another operation. For a powder metal part, that could mean sizing or machining after sintering. Each added operation brings additional production costs that remain with the component throughout its manufacturing life.

Looking at cost early gives engineers more room to evaluate what the part needs to do and identify opportunities for a more cost-effective production approach. By engaging manufacturing, engineering, and quality teams early in the design process, potential opportunities for process optimization can often be identified before production begins.

Where Does Part Design Add Manufacturing Cost?

Manufacturing costs can increase when a design requires processing beyond what the application needs. Once those requirements are part of the design, the added work can follow the component throughout production.

Understanding how design requirements influence manufacturing early in the development process can help engineering teams evaluate opportunities to optimize cost without compromising part performance. Design decisions that can affect manufacturing cost include:

• Tolerances: A tighter tolerance may require sizing or machining when it cannot be maintained through compaction and sintering alone. That added operation then becomes part of the production process every time the component is made.
• Part geometry: Thin walls can create concerns for the part or tooling during production. Sharp features can make tooling more susceptible to chipping or fracture.
• Material requirements: Specifying properties beyond what the application requires can increase material costs or introduce processing that may not be necessary.
• Inspection requirements: Some dimensional requirements may require specialized measuring equipment. Depending on the specification, additional verification may also be needed during production.

This is why application requirements should remain the primary driver of design decisions.

How Can Design Choices Reduce Manufacturing Costs?

Design decisions can sometimes remove work that would otherwise happen later in production. The opportunity depends on what the finished component needs to do.

When engineering and manufacturing teams collaborate early, they can often identify opportunities to simplify production while maintaining required performance characteristics.

Simplifying Part Geometry

Thin walls can increase the risk of cracking in the part or tooling, while sharp edges can create tooling features that are more susceptible to chipping or fracture.

When the design allows, certain features may also be formed during compaction rather than machined afterward. Holes, cavities, and face details are among the features that can sometimes be incorporated directly into the part.

Selecting the Right Material

Material selection should reflect the properties the application requires. Specifying a higher-cost alloy when those properties are not needed adds cost to every component produced.

Material choice can affect processing as well. In some applications, choosing a sinter-hard material can eliminate a separate heat treatment step.

Specifying Tolerances Based on Function

Tolerances can determine how much processing is required after sintering. Depending on what the application can accept:

• Machining may be required for a tighter tolerance.
• Sizing may provide the dimensional control needed.
• Compaction and sintering may be enough when the required tolerance can be maintained without another operation.

This is why Atlas recommends specifying tolerances based on application needs rather than design preferences.

Designing With Manufacturing in Mind

Near-net-shape manufacturing can reduce the amount of work required after sintering. When more of the finished geometry can be incorporated into the tooling, fewer secondary operations may be needed. That can reduce the labor and processing associated with producing the component.

Part Design and the Full Cost of Production

The quoted price of a component does not always show where costs accumulate over the life of a production program. Part design can affect the initial investment as well as the work required each time the component is produced.

Evaluating total production cost rather than piece price alone can provide a more complete understanding of a component's long-term value.

Production volume can change the weight of a design decision. A small amount of added processing may not look significant on a single part, but that cost repeats with every component produced.

Tooling has a longer life to consider. Powder metal tools can produce many parts and may be redressed multiple times as they wear, allowing the same tooling investment to continue supporting production.

Finding Cost-Saving Opportunities Before Production

A design review creates room to consider how a part will be manufactured before those decisions become part of the production process. Rather than looking for one “lowest-cost” design, engineers can compare how different requirements change the manufacturing approach.

The most effective solutions often balance performance, manufacturability, quality, and overall cost objectives.

That review can uncover different paths forward:

• If a tolerance is adjusted, machining may no longer be needed.
• If the geometry changes, a feature may no longer require machining.
• If the material changes, a separate processing step may be avoided.

The right option still depends on what the application can accept. The value of reviewing the design early is having those choices available while changes can still be made.

Designing for Cost Reduction Starts Early

The best time to address manufacturing cost is while there is still flexibility in the part design. A design for cost reduction strategy gives engineers a chance to consider how individual requirements will affect production before those costs become part of the process.

Each design decision should come back to what the application requires. When performance requirements guide those choices, engineers can identify manufacturing steps that may be unnecessary and keep added costs out of production.

Make Cost Part of the Design Conversation

The PM Design Guide offers practical guidance for designing powder metal components with manufacturing in mind, helping you make informed design decisions before production begins.