About Die Casting

FAQ - Alloy Properties

One of the first steps in designing a die cast component is choosing the proper alloy. Typical properties for the most commonly used alloys are shown on the following charts.

  Aluminum Brass Magnesium Zinc
Tensile strength, psi x 1000 47 55 34 41
Yield strength, psi x 100 (0.2 pct offset) 23 30 23 —
Shear strength, psi x 1000 28 37 20 31
Fatigue strength, psi x 1000 20 25 14 7
Elongation, pct in 2 in. 3.50 15 3.0 10
Hardness (Brinell) 80 91 63 82
Specific gravity 2.71 8.30 1.80 6.60
Weight, lb/cu. in. 0.098 0.305 0.066 0.24
Melting point (liquid), °F 1100 1670 1105 728
Thermal conductivity, CG5 0.23 0.21 0.16 0.27
Thermal expansion, in./in./°F x 106 12.1 12.0 15.0 15.2
Electrical conductivity,
pct of copper standard		 27 20 10 27
Modulus of elasticity, psi x 106 10.3 15 6.5 —
Impact strength (Charpy), ft/lb 3.0 40 2.0 43.0


Characteristics of Die Casting Alloys
  Aluminum Brass Magnesium Zinc
Dimensional stability Good Excellent Excellent Good
Corrosion resistance Good Excellent Fair Fair
Casting ease Good Fair Good Excellent
Part complexity Good Fair Good Excellent
Dimensional accuracy Good Fair Excellent Excellent
Die cost Medium High Medium Low
Machining cost Low Medium Low Low
Finishing cost Medium Low High Low
Chart does not intend to compare metals. Its purpose is to show the most advantageous characteristics of each specific metal. For more specific information, refer to NADCA Product Standards for Die Casting.

 

Dimensional and Weight Limit
  Aluminum Brass Magnesium Zinc
Maximum weight, lb. 70 10 44 75
Minimum wall thickness, large casting, in. 0.080 0.090 0.100 0.035
Minimum wall thickness, small casting, inc. 0.040 0.055 0.040 0.015
Minimum variation per in. of diameter or length from drawing dimensions over one in. 0.0015 0.009 0.0015 0.001
Cast threads, max. per in. external 24 10 24 32
Cored holes, min. diameter in. 0.080 0.250 0.080 0.050

Finishing: Decorative
  Aluminum Brass Magnesium Zinc
Chrome plating Fair Excellent Fair Excellent
Black chrome plating Fair Excellent — Excellent
Colored plating Fair — — Excellent
Mechanical - polishing & buffing Excellent Excellent Excellent Excellent
Lacquers, enamels, epoxies & acrylics Excellent Excellent Excellent Excellent
Anodizing Fair — — —

For more specific information, refer to NADCA Product Specification Standards for Die Castings.