Shenzhen Alu Rapid Prototype Precision Co., Ltd.
Industry News
Strength of Die Cast Zinc
Zinc die casting alloys (commonly called Zamak alloys) offer a solid combination of strength and versatility. Here's a breakdown:
Key Mechanical Properties
Property | Zamak 3 | Zamak 5 | Zamak 2 | ZA-8 |
Tensile Strength | 268 MPa (38,900 psi) | 331 MPa (48,000 psi) | 359 MPa (52,000 psi) | 374 MPa (54,000 psi) |
Yield Strength | 207 MPa (30,000 psi) | 269 MPa (39,000 psi) | 317 MPa (46,000 psi) | 290 MPa (42,000 psi) |
Hardness (Brinell) | 82 HB | 91 HB | 100 HB | 103 HB |
Elongation | 10% | 7% | 7% | 6–10% |
Impact Strength | 58 J (43 ft·lb) | 65 J (48 ft·lb) | 58 J (43 ft·lb) | 54 J (40 ft·lb) |
Zamak 3 is the most commonly used alloy (North American standard baseline)
How It Compares to Other Materials
Material | Tensile Strength |
Zamak 3 (zinc) | ~268 MPa |
A380 Aluminum | ~324 MPa |
AZ91D Magnesium | ~230 MPa |
Mild Steel | ~400–550 MPa |
Polycarbonate plastic | ~55–75 MPa |
Zinc is stronger than most plastics and magnesium, roughly comparable to aluminum, but weaker than steel.
Strengths of Zinc as a Die Cast Material
Excellent impact resistance — better than aluminum at room temperature
Good creep resistance at moderate temperatures
Superior thin-wall capability — can cast walls as thin as 0.3mm
Self-lubricating properties
Very good fatigue strength for cyclic loading applications
Weaknesses / Limitations
Temperature sensitive — loses strength above ~100°C (212°F); not suitable for high-heat environments
Heavier than aluminum (density ~6.6 g/cm³ vs aluminum's ~2.7 g/cm³)
Creep under sustained load at elevated temperatures
Can corrode in harsh environments without surface treatment
Common Applications Based on Its Strength Profile
Automotive: door handles, lock housings, fuel system parts
Hardware: padlocks, hinges, brackets
Electronics: connectors, housings
Consumer goods: belt buckles, zippers, toys (e.g., classic die-cast toy cars)
Bottom Line
Die cast zinc is a medium-strength engineering material — strong enough for most structural hardware and mechanical components, but not suited for high-stress or high-temperature applications where aluminum, magnesium, or steel would be preferred.