Wall thickness and flow
Uniform wall thickness lets metal flow evenly through the die. Thick-to-thin transitions create uneven flow, differential cooling and potential distortion. Where thick sections are structurally needed, consider ribbed or hollow alternatives that use material more efficiently.
- Keep walls as uniform as the function allows
- Aim for wall thickness ratios the press can run comfortably
- Use ribs and flanges instead of solid mass
- Place thin walls away from thick junctions where possible
Radii and symmetry
Sharp internal corners concentrate stress and accelerate die wear. Generous internal radii run better and last longer. Symmetric shapes balance flow and cooling — where asymmetry is unavoidable, discuss it with the die designer early.
Hollows and press limits
Hollow sections need bridge or porthole dies that support internal mandrels — achievable but with limits on wall thickness and size. The circumscribing circle of your design determines the press class required; oversized designs limit supplier choice and raise cost.
Design for downstream operations
Extrusion design is assembly design. Integrate fastening features, cable channels and sealing surfaces where the process allows; leave machining datums for features that must be precise. The profile should arrive as close to a finished part as the process economically permits.