Aluminium Die Casting — Complete Guide for Manufacturers 2026

Aluminium die casting (high-pressure die casting, HPDC) is the dominant manufacturing method when manufacturers need complex aluminium components in medium to high volumes. The method delivers high dimensional accuracy, good surface finish directly from the tool, and a unit cost that is hard to beat for runs exceeding 5,000–10,000 parts. This guide covers how the process works from a technical standpoint, which alloys are relevant, what tolerances can realistically be achieved, what the economics look like — and when it pays to source from Asian foundries rather than European ones.

This guide is intended for buyers, production managers and design engineers who are already familiar with the basics of die casting and need specific, practical information to make sourcing and design decisions.

How aluminium die casting works

In high-pressure die casting, molten aluminium is injected into a hardened steel die at pressures typically between 400 and 1,200 bar. The metal fills the cavity in milliseconds, solidifies under pressure, and the die opens to eject the finished component. Cycle times range from 30 seconds to 2 minutes depending on component size and wall thickness.

The process is inherently suited for thin-walled components (from 0.8 mm) with complex geometries, ribs, bosses and undercuts. Draft angles of 1–3 degrees are typically required for ejection.

Aluminium alloys for die casting

AlSi9Cu3 (EN AC-46000 / A380)

The most widely used die casting alloy globally. Good castability, moderate strength, and acceptable corrosion resistance. Suitable for structural and non-structural components alike.

AlSi12 (EN AC-44300 / A413)

Excellent fluidity and pressure tightness. Preferred for thin-walled and complex components where filling behaviour is critical.

AlSi10Mg (EN AC-43400 / A360)

Higher ductility and improved mechanical properties after T6 heat treatment. Used where structural performance is prioritised.

AlMg5Si2Mn (Magsimal-59)

A high-performance alloy with excellent elongation and energy absorption. Increasingly used in automotive structural crash components.

Tolerances and surface finish

Standard tolerances for HPDC aluminium components follow ISO 8062 CT6–CT7 as cast. For critical dimensions, machining allowances of 0.5–1.0 mm are typically added.

Linear dimensions: ±0.1–0.3 mm (as cast)
Flatness: 0.1–0.3 mm per 100 mm
Surface roughness: Ra 1.6–6.3 µm (as cast)
Wall thickness: minimum 0.8 mm, typical 1.5–3.0 mm

Tooling economics

Die casting tooling is a significant upfront investment. A typical single-cavity die for a medium-sized automotive component costs EUR 15,000–50,000 from a European toolmaker, or EUR 8,000–25,000 from a qualified Chinese or Indian tool shop. Multi-cavity dies can double or triple these figures.

Tooling amortisation is the key economic driver. At 50,000 parts per year, even an expensive European die becomes economical. Below 5,000 parts, alternative methods such as gravity die casting or sand casting should be evaluated.

When to source from Asia

Asian foundries — particularly in China (Ningbo, Dongguan, Wenzhou) — offer 30–50% lower unit costs for HPDC components compared to European producers. The savings come from lower labour costs, integrated toolmaking, and established supply chains for post-processing.

Key success factors for Asian sourcing:

Clear, unambiguous 2D drawings with GD&T tolerances
First Article Inspection (FAI) per PPAP or equivalent
Third-party quality inspection before shipment
Material certificates with chemical analysis and mechanical test results
A sourcing partner who manages the supplier relationship on-site

Traficator’s role

Traficator manages the complete supply chain for die-cast aluminium components — from alloy selection and die design review to supplier qualification, sample approval and serial delivery. We work with qualified HPDC foundries in Sweden, Central Europe and Asia to match the right producer to your application and volume requirements.

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