01Die types
| Die | Used for | How it works |
|---|---|---|
| Solid (flat) die | Open shapes: angles, channels, heat sinks | A single plate with the profile opening; bearing lengths balance metal flow. |
| Semi-hollow die | Deep slots and partly enclosed voids | Supports the die tongue so it survives extrusion pressure. |
| Porthole (bridge) die | Tubes and hollow profiles | Metal splits around bridges, re-welds in a welding chamber and flows around a mandrel. |
| Multi-cavity die | Small profiles in volume | Several identical openings extrude multiple strands at once. |
02Design for manufacturing review
Before a die is designed, engineers check the section against what the press and die can reliably do: wall balance, corner radii, tongue ratios, circumscribing circle and tolerances. Small changes at this stage — a radius here, a balanced wall there — often reduce die cost, speed up extrusion and improve surface quality.
The design guide lists the rules we check.
03Trials, correction and approval
Trial extrusion
The new die runs first samples under production conditions.
Measurement
Samples are measured against your drawing; results go into a dimensional report.
Correction
Bearing lengths and flow are adjusted if dimensions or surface need it.
Approval
You approve the samples — the reference for every production run.
04Die life, maintenance and storage
Dies wear with use. Bearing surfaces are nitrided for wear resistance, re-nitrided between campaigns, and inspected before each run. A customer's die is reserved for that customer's profile, stored at the plant between orders and maintained for repeat production. Ownership and storage terms are stated in each quotation.
05Frequently asked questions
How much does an aluminum extrusion die cost?
Die cost depends on size, complexity and die type — hollow and multi-hollow dies cost more than solid dies. For most small and medium profiles, it is a modest one-time charge compared with casting or molding tooling. See our die cost guide.
How long does an extrusion die last?
Die life depends on alloy, section complexity and maintenance. Nitriding and regular maintenance extend it; when a die eventually wears, a replacement is made from the same design.
Can you use an existing die from another supplier?
Dies are designed for a specific press container and die stack, so a die from another plant usually cannot be used directly. We can make a new die to the same drawing.
Last updated September 17, 2026 · Reviewed by the CharMax Aluminum engineering team