TECHNICAL GUIDE

Die Casting Mould Maintenance

March 2026 · 6 min read · Tweeler AB

Tweeler AB is a precision aluminium die casting company based in Stockholm, Sweden, specialising in custom mould design, HPDC, re-engineering, and global logistics.

A die casting mould is a significant capital investment — often €5,000 to €50,000 or more. Proper maintenance protects that investment, extends tool life, and keeps part quality consistent over hundreds of thousands of cycles.

How Long Should a Die Casting Mould Last?

The lifespan of an aluminium die casting mould depends on the alloy, part complexity, and maintenance. As a general guide, a well-maintained H13 steel mould casting aluminium can be expected to produce:

Part size / complexityTypical mould life
Small, simple parts200,000–500,000+ shots
Medium parts100,000–200,000 shots
Large or complex parts50,000–100,000 shots

Why Aluminium Is Hard on Moulds

Aluminium is cast at around 660–700°C and injected at high velocity and pressure. This subjects the mould to repeated thermal cycling, erosion from the fast-moving metal, and chemical attack (soldering, where aluminium bonds to the steel surface). Maintenance slows that degradation.

Preventive Maintenance Schedule

Every shift / daily

Periodic (every 5,000–20,000 shots)

Major maintenance (as needed)

Heat Checking — The Most Common Wear Mode

Heat checking is a network of fine surface cracks that develops on the mould cavity from repeated thermal cycling. It is the most common end-of-life mechanism for aluminium die casting moulds. Caught early, the affected area can sometimes be polished or re-worked. Left unchecked, the cracks deepen and the cavity must be welded and re-machined or replaced.

Soldering

Soldering occurs when molten aluminium chemically bonds to the steel mould surface, causing parts to stick and tear. It is managed through correct release agent application, proper mould temperature, optimised gate design, and surface treatments such as nitriding.

Proper Storage Between Runs

Before storage, the mould should be cleaned, coated with a rust preventive, and stored in a dry, temperature-stable environment. Cooling lines should be blown out to prevent internal corrosion.

Signs Your Mould Needs Attention

Tweeler AB maintains all customer tooling to a documented preventive maintenance schedule — protecting your investment and keeping part quality consistent shot after shot. Your mould remains your property and is cared for as such.

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