Shenzhen Alu Rapid Prototype Precision Co., Ltd.

No, die-cast zinc does not rust in the typical sense — but it can corrode.

Here's the key distinction:

1.Rust specifically refers to the red iron oxide that forms when iron or steel (iron alloys) react with oxygen and moisture. Zinc is not iron, so it cannot "rust."

2.Zinc does corrode, however, when exposed to moisture and air. The corrosion product on zinc is usually a dull gray or white powdery layer called zinc oxide or zinc carbonate (often referred to as "white rust" in humid conditions). This layer is actually somewhat protective — it tends to slow down further corrosion compared to iron rust, which flakes off and exposes fresh metal.

Behavior of typical die-cast zinc alloys (e.g., Zamak 3, Zamak 5, ZA-8):

In practice:

1.Most die-cast zinc parts (doorknobs, carburetors, toys, faucets, etc.) are plated (chrome, nickel, powder coat, paint) precisely because the raw alloy will eventually develop an unattractive dull or white layer if left exposed.

2.Unplated die-cast zinc left outdoors for years will look chalky/white/gray but usually won’t fall apart the way rusted steel does.

Short answer:

Die-cast zinc does not rust (no red rust), but it will corrode over time, forming a white or gray layer, especially in damp or polluted environments. Proper plating or coating prevents this almost entirely.