Key Design Principles for Optimizing Metal 3D Printed Parts

Metal 3D printing is reshaping manufacturing, with sales of metal additive‑manufacturing systems jumping 80% since 2017. The technology gives designers unparalleled freedom to craft organic shapes and lightweight structures that would be impossible with conventional methods.

To fully exploit this capability, you must adopt a new design mindset. Traditional rules no longer apply; instead, a set of best practices is essential for creating robust, high‑quality metal parts.

Below are the six critical design considerations that will help you get the most out of your metal 3D prints.

1. Wall Thickness

Wall thickness is a foundational parameter. A minimum of 0.4 mm is recommended to avoid fragile prints or internal stress buildup that can lead to cracking. The exact optimum depends on the chosen material and printer settings. If you need thicker walls, consider lattice or honeycomb infill to save material and reduce build time.

2. Support Structures

Supports are almost always required in metal 3D printing. They anchor the part to the build plate and dissipate heat, preventing residual stresses. For internal features such as horizontal holes, angled supports minimize contact area and simplify post‑processing. Design supports to taper and stay tubular to ease removal.

3. Overhangs and Self‑Supporting Angles

Overhangs longer than 0.5 mm or angled below 45° typically need supports to avoid collapse. Fillets or chamfers can eliminate problematic overhangs, and positioning features on the upward side of the build improves surface finish.

4. Part Orientation

Experimenting with orientation is the best way to reduce supports. For hollow tubes, vertical or angled placement saves space and material. Remember that downward‑facing surfaces (down‑skins) have rougher finishes; orient critical details upward.

5. Channels and Holes

Metal AM excels at creating channels and holes. The minimum printable diameter for powder‑bed processes is 0.4 mm. Holes or tubes over 10 mm usually require supports. Perfectly round horizontal holes are challenging; redesign them as teardrop or diamond shapes. Don’t forget escape holes for powder removal—2‑5 mm is ideal.

6. Topology Optimisation & Generative Design

Topology optimisation and generative design harness additive manufacturing’s freedom to produce lightweight, strong parts. Use mathematical models to distribute material efficiently, and explore nature‑inspired patterns to explore every viable solution.

Shifting the Design Paradigm

Designing for metal 3D printing demands deep knowledge of the technology’s strengths and limits. Integrating these guidelines early in the design process maximises success, reduces costs, and cuts waste.

For more on metal 3D printing, check out our comprehensive guide to metal 3D printing and our introduction to DMLS.