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 linked 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
|
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), 癋 |
1100
|
1670
|
1105
|
728
|
|
Thermal conductivity, CG5
|
0.23
|
0.21
|
0.16
|
0.27
|
|
Thermal expansion, in./in./癋 x 106
|
12.1
|
12.0
|
15.0
|
15.2
|
|
Electrical conductivity, |
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. |
||||
|
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
|
� |
� |
� |
