Aluminum Extrusion Key Design Considerations
Aluminum extrusions are available in an extremely wide range of shapes and sizes, and extrusion tooling is generally far lower cost than stamping dies. However, every manufacturing process has some limitations. For aluminum extrusions, there are practical limits; some designs prove very challenging to extrude, while minor tweaks to an extrusion profile design can often yield significant benefits in extrudability, and consequently, lower cost.
Below are several factors to consider when designing with aluminum extrusions:
Overall Cross Section Size
One common measurement of the size of an extrusion is the diameter of the smallest circle that will entirely enclose its cross-section, or its circumscribing circle diameter (CCD). The dimension is one factor in the economics of an extrusion. Most common profiles are less than 12 inches in diameter, while a few extruders are capable of producing extrusions with a much larger CCD, some as large as 32 inches. See the Press availability chart below.
The dimension of the profile is one factor in the economics of an extrusion. In general, extrusions are most economical when they fit within a CCD between one and ten inches. Profiles below 8-inches of CCD reduce costs significantly.
The weight-per-foot of a profile is important because of the effect it has on profitable press operation. Is the profile too heavy? Is it too light? Many factors affect press operation and the press size required to extrude a profile. Your extrusion partner will provide the information you need to improve your profile design to extrude cost effectively.
Generally, the design is greatly enhanced if the profile CCD is kept under 8 inches and the wt/ft is 3 pounds or less.
Good Aluminum Extrusion Design Practices
- Balanced walls
- Avoid/minimize hollows
- Generous tapers
- Practice symmetry/minimize asymmetrical detail
- Use grooves, webs, and ribs
- Minimize perimeter/cross-section ratio
Availability of press sizes
Keep in mind the various profile circle size/area/weight combinations and the press sizes available to handle them. Below is a chart showing the general availability of press sizes in North America. Keep this in mind when designing your profile as it will affect the extrusion cost.
ALUMINUM EXTRUSION MANUAL
191 pages of aluminum advantages, applications, sustainability, design tips, and more!