Zamak Injection Molding: What It Really Means for Your Parts

Is zamak injection molded?

Short answer: no — not in the plastics sense, but yes in a literal one. Plastic injection molding melts a thermoplastic and forces it into a mold. Zamak (the family of zinc-aluminium alloys standardised under EN 12844 and ASTM B86) is a metal, and metals are not “injection molded” like polymers. Zamak parts are made by hot-chamber die casting.

Where the confusion comes from is real, though: in hot-chamber die casting the molten zamak is injected — a plunger pushes the liquid metal through a gooseneck and into the die cavity under high pressure. So “zinc injection” or “zamak injection” is loosely accurate as a description of the mechanism. It is just not the same manufacturing route as plastic injection molding, and it is not “Metal Injection Molding” (MIM) either.

Why people say “injection”

Zamak melts at roughly 380–390 °C and is die cast at around 400–420 °C — low enough to keep the metal liquid right inside the casting machine. The molten alloy sits in a heated pot; a plunger injects a shot of liquid zamak into the steel die at every cycle, the part solidifies in a fraction of a second, and the die opens. Because the metal is literally injected, operators and buyers often reach for the word “injection”. It captures the feel of the process — fast, pressurised, repeatable — even if the correct industry term is hot-chamber die casting.

Zamak die casting vs plastic injection molding vs MIM

These three processes get conflated under “injection molding”. They are not interchangeable. Here is the honest comparison:

Process	Material	How it works	Typical parts
Hot-chamber zinc die casting (what “zamak injection” means)	Zamak / zinc alloys (ZP3, ZP5, ZP2, ZP8 — EN 12844)	Molten zamak (cast at ~400–420 °C) injected under pressure into a steel die via a gooseneck and plunger; solidifies in seconds.	Locks & security hardware, automotive, connectors, fittings, decorative components
Plastic injection molding	Thermoplastics (ABS, PA, PP…)	Molten polymer (~200–300 °C) injected into a mold; cools and sets.	Plastic housings, consumer goods, lightweight enclosures
Metal Injection Molding (MIM)	Metal powder + polymer binder (mostly steel, stainless, titanium)	Powder-binder feedstock injection molded, then debound and sintered at high temperature.	Very small, complex steel parts; rarely used for zinc/zamak

The practical takeaway: if your part is zamak, you want hot-chamber die casting, not plastic injection molding and almost never MIM.

How hot-chamber zamak “injection” actually works

The cycle is short and well suited to high volumes:

1. Melt & hold — zamak is kept molten in a heated pot integrated with the machine.
2. Inject — a plunger forces a measured shot of liquid metal through the gooseneck into the closed steel die under pressure.
3. Solidify — the thin-walled part sets almost immediately thanks to the high cooling rate of the steel die.
4. Eject — the die opens, the part is ejected, and the cycle repeats — often several times per minute.

This is exactly why hot-chamber die casting is the standard route for zinc: the low melting point lets the metal live inside the machine, so cycles are fast and the process is economical at scale. For the full technical breakdown see our guide to the hot-chamber die casting process for zamak.

When to choose zamak die casting

Zamak die casting is a strong fit when you need:

• Complex, thin-walled geometries in a single shot, with good detail and tight tolerances.
• High strength and dimensional stability — see the mechanical properties of zamak alloys and how to choose the right alloy by application.
• A surface ready for plating or painting — zamak takes a wide range of finishes well.
• Cost efficiency at medium-to-high volumes, thanks to fast cycle times and long die life.

FAQ

Can zamak be injection molded like plastic?
No. Plastic injection molding is for thermoplastics. Zamak is cast by hot-chamber die casting, where molten metal is injected into a steel die.

So why is it called “zamak injection”?
Because the molten zamak is genuinely injected under pressure into the die. The mechanism resembles injection; the material and process do not match plastic molding.

Is zamak the same as Metal Injection Molding (MIM)?
No. MIM uses metal powder mixed with a binder, then sintering. It targets small complex steel or titanium parts and is rarely used for zinc alloys.

What temperature is zamak processed at?
Zamak melts at roughly 380–390 °C and is die cast at around 400–420 °C, which is what makes the efficient hot-chamber process possible.