Zamak Die Casting: Complete Technical Guide

Zinc alloys, hot chamber process, mechanical properties and industrial applications

What is Zamak?

Zamak is a family of zinc-based alloys composed primarily of zinc, aluminium, magnesium and copper. The name derives from the German words: Zink (Zinc), Aluminium, Magnesium, Kupfer (Copper).

These alloys are specifically designed for die casting, offering excellent fluidity, dimensional stability and surface finish. Zamak produces high-precision components with tolerances of 0.05 mm directly from the mould, with minimal secondary machining.

Origin and Composition

The name Zamak is an acronym of the German words for its main components: Zink (zinc), Aluminium (aluminium), Magnesium (magnesium) and Kupfer (copper). The alloy is composed of 94–96% high-purity zinc (99.99%), with controlled additions of aluminium (3.5–4.3%), magnesium (0.02–0.06%) and copper (0–3% depending on the grade). This composition gives zamak exceptional mechanical properties for die casting.

Zamak was developed in the 1930s by the New Jersey Zinc Company as an alternative to the zinc alloys available at the time, which suffered from intergranular corrosion due to impurities. The use of high-purity zinc solved this problem, making zamak alloys stable over time and suitable for structural components.

Today zamak is the most die-cast alloy in the world after aluminium, with applications spanning automotive, electronics, security hardware and furniture. Its combination of low cost, high precision and excellent surface finish has made it the material of choice for millions of industrial components manufactured every year across Europe, Asia and the Americas.

At Micrometal, we have been specialising in zamak hot chamber die casting since 1991. With over 30 years of experience, 11 presses and a production capacity of 75,000 kg per month, we support our clients from component design through to serial production and surface finishing.

Key Properties

The characteristics that make zamak ideal for industrial die casting include:

• Low melting point (380–420 °C) — approximately 260 °C lower than aluminium, with energy savings of 30%
• Excellent fluidity — allows filling thin-wall cavities down to 0.3 mm wall thickness
• Dimensional precision — achievable tolerances of ±0.05 mm without secondary machining
• Superior surface finish — Ra 0.8–1.6 µm directly from the mould
• Mechanical strength — from 280 MPa (ZP3) to 374 MPa (ZP2), comparable to many mild steels
• Full recyclability — zamak is 100% recyclable without loss of properties

Hot Chamber Die Casting Process

Zamak alloys are processed exclusively by hot chamber die casting (HCDC), the most efficient process for zinc-based alloys.

How Hot Chamber Casting Works

In hot chamber die casting the injection system is immersed in the molten metal inside the melting furnace. This is possible because zamak melts at temperatures (380–420 °C) compatible with the steel components of the injection system.

Unlike cold chamber die casting (used for aluminium), there is no need to transfer molten metal from the furnace to the injection chamber — the piston pumps directly from the melting pot, speeding up the production cycle.

A typical zamak hot chamber die casting cycle lasts between 15 and 45 seconds, depending on part complexity, and consists of four main phases:

1. Mould closing — the two halves of the die are clamped by the press with forces from 25 to 90 tonnes
2. Injection — the piston pushes molten zamak into the die cavity at speeds of 2–5 m/s and pressures of 150–350 bar
3. Cooling and solidification — zamak solidifies rapidly (3–15 seconds) thanks to the die cooling system
4. Opening and ejection — the die opens and ejector pins expel the finished part

Advantages of the Hot Chamber Process

Compared with cold chamber casting (used for aluminium and magnesium), hot chamber casting offers significant advantages for zamak: 40–60% faster cycle times, less metal oxidation, much longer die life (up to 2 million shots versus 100,000–200,000 for aluminium) and 30% lower energy consumption.

These advantages translate into lower per-part costs, especially for medium and large production runs.

At Micrometal we use 11 hot chamber presses from four leading manufacturers — Frech, Agrati, Colosio and Italpresse — with clamping forces from 25 to 90 tonnes, covering the full range of components from 5 g micro-parts to 700 g structural components.

Key process advantages: the low melting temperature (~400 °C) compared with aluminium (~660 °C) reduces energy consumption and die wear, with die lives from 750,000 to 2,000,000 shots.

Discover our zamak die casting machinery →

Zamak Alloy Grades

The main grades used in hot chamber die casting (HCDC), standardised according to EN 12844:

ZP3 (Zamak 3) — The Universal Alloy

ZP3 is the most widely used zamak alloy in the world, accounting for approximately 70% of all zinc die casting production. With a composition of 4% aluminium, 0.04% magnesium and no copper, it offers the best balance of mechanical properties, casting fluidity and long-term dimensional stability.

Tensile strength: 280 MPa, elongation: 10%, hardness: 82 HB. It is the preferred choice for lock and security components, where dimensional stability is critical.

ZP5 (Zamak 5) — Superior Strength

ZP5 adds 0.75–1.25% copper to the ZP3 composition, increasing tensile strength to 331 MPa with an elongation of 3%. The copper provides greater wear and fatigue resistance, making it ideal for automotive components subject to cyclic loads.

In our experience, ZP5 requires tighter control of melting temperatures (±3 °C) to avoid copper segregation.

ZP2 (Zamak 2) — Maximum Performance

With 2.5–3% copper, ZP2 achieves 374 MPa tensile strength and 95 HB hardness — the peak mechanical performance among standard zamak alloys. It is specifically suited for gears, cams and components subject to heavy wear.

The reduced elongation (2%) requires attention during design to avoid stress concentrations.

ZP8 (Zamak 8 / ZA-8)

ZP8 is distinguished by its 8.4% aluminium content, which gives it the highest mechanical strength among all hot chamber die-castable zamak alloys. With 374 MPa tensile strength and lower density (6.3 g/cm³ versus 6.6 g/cm³ for ZP3), it is attractive for applications where the strength-to-weight ratio is a priority.

However, its lower fluidity makes it less suitable for highly complex geometries or very thin walls.

For a detailed alloy selection guide, see our article Zamak Alloys ZP3, ZP5, ZP2, ZP8: Differences and Applications.

Zamak 3 is the most widely used grade thanks to its optimal balance of mechanical strength, fluidity and cost. Zamak 5 is preferred in automotive and structural applications requiring higher strength. Zamak 7 excels in thin-walled, aesthetically demanding components.

Zamak vs Other Materials — Key Properties

Comparative data from EN 12844 (Zamak), EN 1706 (Aluminium), EN 1753 (Magnesium) and IZA sources:

Material selection in die casting depends on multiple factors: required mechanical properties, geometric complexity, production volumes, costs and surface finish requirements. Zamak competes primarily with aluminium, brass and engineering plastics.

Zamak vs Aluminium

Zamak offers decisive advantages over aluminium in die casting: 40% lower melting temperature (400 °C versus 660 °C) with 30% energy savings, 10–20× longer die life (2 million versus 100,000–200,000 shots), better dimensional precision (±0.05 mm versus ±0.1 mm) and faster cycle times.

Aluminium is preferable only when weight is the dominant factor (density 2.7 versus 6.6 g/cm³) or for operating temperatures above 120 °C.

Learn more: Advantages of zamak die casting vs aluminium →

Zamak vs Brass

Compared with brass, zamak costs 30–50% less for the same volume, has a much lower melting point (400 °C versus 900–940 °C) and allows more complex geometries. Brass is superior for corrosion resistance in marine environments and for high-temperature applications, but for the majority of industrial components zamak is the more economical and versatile choice.

Learn more: Zamak vs Brass — which alloy to choose →

Zamak vs Plastic

Zamak surpasses engineering plastics in mechanical strength (280–374 MPa versus 30–80 MPa), rigidity, thermal resistance, EMI shielding and perceived premium quality. Plastic is preferable for high volumes of lightweight parts without stringent mechanical requirements. For technical components requiring tight tolerances, wear resistance and metallic finishes, zamak is the best choice.

Learn more: Zamak vs Plastic — when die casting beats injection moulding →

Advantages of Zamak Die Casting

The advantages of zamak die casting extend well beyond material properties. The entire production process offers economic and quality benefits that make it competitive for a wide range of B2B applications.

Economic Advantages

• Amortisable die cost — zamak dies last up to 2 million shots, allowing the investment to be amortised over large production runs
• Fast cycle times — 15–45 seconds per part, with hourly output of 80–240 parts
• Reduced secondary machining — tolerances of ±0.05 mm eliminate the need for CNC reworking in most cases
• Energy savings — 30% lower consumption compared with aluminium die casting

Technical Advantages

• Complex geometries — threads, undercuts and thin ribs achievable directly in the die
• Thin walls — wall thicknesses down to 0.3 mm, impossible with aluminium or brass
• Inserts and over-moulding — metal, rubber and plastic inserts can be cast in a single cycle
• Excellent surface finish — ideal for galvanic treatments (chrome, nickel, zinc plating) without additional preparation

Industrial Applications

The versatility of zamak makes it suitable for an exceptionally wide range of industrial sectors. At Micrometal, since 1991 we have served clients in over 10 sectors with components ranging from 5 g micro-parts to 700 g structural components.

Other Sectors

Gas valves and regulators — valve bodies, levers, regulator components. Sealing and corrosion resistance requirements.

Furniture and lighting — hinges, handles, lamp bases, accessories. Superior aesthetic finish.

Instrumentation and sensors — housings, brackets, precision components for measuring instruments.

Taps and valves — components for taps and valve assemblies.

Household appliances — mechanical and structural parts for domestic appliances.

Fashion and leather goods — buckles, clasps, high-end accessories.

Each sector requires specific design and quality control expertise. Our ISO 9001 certification guarantees full traceability of every production batch. From the initial feasibility study to the final delivery, our technical team works alongside clients to optimise part geometry, select the most appropriate alloy and define the most efficient production process.

The zamak die casting industry continues to grow, driven by the demand for cost-effective, high-precision components that can replace more expensive machined parts. With increasing environmental awareness, the full recyclability of zamak adds a sustainability advantage that many manufacturers are now actively seeking.

Limitations of Zamak

Understanding the limitations of zamak is essential for correct design and to avoid production issues. A good die casting supplier must be transparent about these aspects.

Limited thermal resistance (~120 °C) — above this threshold mechanical properties degrade. For high-temperature applications, aluminium or steel are preferable.

High density (6.7 g/cm³) — zamak is approximately 2.4 times heavier than aluminium (2.79 g/cm³). For weight-critical applications, other materials are more suitable.

Creep under sustained load — under long-term constant static loads, zamak can deform slowly. Design must account for this in structural components under permanent load.

Corrosion resistance — requires surface treatment in aggressive or outdoor environments. Galvanic treatments solve this issue in most cases.

These limitations are manageable with correct DFM (Design for Manufacturing) practices. Our engineering department supports clients in the co-design phase to identify and resolve potential issues before die manufacture. It is important to note that many of these limitations can be mitigated through careful alloy selection. For example, ZP8 offers improved creep resistance compared with ZP3, while appropriate surface treatments can extend the service life of zamak components in challenging environments to well over 10 years.

Dimensional Tolerances and Surface Quality

One of the most significant advantages of zamak die casting is the ability to achieve very tight dimensional tolerances directly from the mould, without secondary machining operations. This translates into lower production costs and shorter lead times.

The tolerances achievable with zamak hot chamber die casting depend on the nominal dimension, part geometry and die condition. Below is a summary table of standard tolerances according to EN 12844:

Surface roughness directly from the mould typically ranges from Ra 0.8 to Ra 1.6 µm, comparable to fine machining. This surface quality makes zamak particularly suitable for galvanic treatments such as chrome plating, nickel plating and zinc plating, which require a smooth and uniform substrate for optimal adhesion.

For components requiring even tighter tolerances on specific dimensions, CNC machining operations can be performed on the cast part. However, in our experience at Micrometal, over 80% of components require no secondary machining — a significant cost advantage over aluminium and brass die casting. The minimum achievable wall thickness for zamak die casting is 0.3 mm, significantly thinner than aluminium (1.2–1.5 mm) or magnesium (1.0 mm).

FAQ — Frequently Asked Questions

Need zamak die cast components?

Upload your technical drawing and receive a quote within 24/48 hours.