Shenzhen Alu Rapid Prototype Precision Co., Ltd.

Zinc is considered one of the best metals for die casting (especially hot-chamber die casting) for several key reasons:

1. Low Melting Point (~420 °C / 787 °F)

A.Zinc melts at a much lower temperature than aluminum (660 °C), brass (900–940 °C), or magnesium (~650 °C).

B.This allows the use of hot-chamber die casting, where the injection system is submerged in molten metal. Hot-chamber is faster, more automated, and has much higher production rates (often 2–5× faster than cold-chamber processes used for aluminum).

2. Excellent Fluidity

A.Molten zinc has very low viscosity and flows extremely well into thin walls and intricate details.

B.Typical wall thicknesses: 0.3–0.8 mm (vs. 1.5–2.0 mm common with aluminum), enabling lighter, thinner, and more complex parts.

3. Long Die Life

A.Because of the low melting temperature and low attack on steel dies, zinc die-casting dies last dramatically longer。

B.Lower die wear = lower tooling costs per part at high volumes.

4. Excellent Dimensional Accuracy and Surface Finish

A.As-cast tolerances as tight as ±0.025 mm (±0.001 in) are routine.

B.Smooth surfaces often require no secondary machining and can be plated (chrome, nickel, etc.) directly with minimal prep.

5. High Strength and Hardness (for a die-cast metal)

A.Common alloys (Zamaks 3, 5, 7 and ZA-8)

B.Stronger and harder than most aluminum die-casting alloys (e.g., A380 is ~160 MPa yield).

6. Fast Cycle Times

A.Combination of low melting point, fast solidification, and hot-chamber process gives cycle times as low as 5–15 seconds (vs. 30–60+ seconds for aluminum cold-chamber).

7. Good Corrosion Resistance (especially with modern alloys and coatings)

A.Zamak alloys resist atmospheric corrosion well, and decorative chrome plating adheres extremely well to zinc.

Typical Applications Where Zinc Excels

A.Automotive: door handles, lock components, seat belt parts

B.Electronics: connector housings, EMI/RFI shielding

C.Consumer goods: zippers, bathroom fixtures, power-tool housings, toys

D.Anywhere thin walls, high production volume, and excellent surface finish are needed.

Main Drawbacks (for balance)

A.Higher density than aluminum or magnesium (~6.6–7.1 g/cm³ vs. 2.7 for Al)

B.Lower maximum operating temperature (~100–120 °C continuous before creep becomes an issue)

C.Slightly higher material cost per kg (though often offset by thinner walls and faster cycles)