Aluminum Alloy Comparison
(ASTM B26/B26M): A356.0-T6 & 319.0-F
Two proven solutions—one built for performance + leak-tight reliability, one built for machining + production stability
When you choose an alloy, you’re choosing a solution path for strength, pressure integrity potential, machinability, and long-term reliability. For sand castings, the mechanical minimums below are derived from ASTM B26/B26M (separately cast test bars).
Which alloy is best for your application?
A356.0-T6
Performance + ductility for demanding, leak-tight designs
Best fit when you need: higher mechanical performance, toughness/elongation headroom, and strong leak-tight potential when process control is dialed in.
319.0-F
Machining + stable, cost-effective production baseline
Best fit when you need: machining-friendly castings and straightforward “as-cast” performance (no heat treat) with repeatable results.
Minimum mechanicals + typical hardness
Ultimate Tensile Strength
34 ksi (235 MPa)
23 ksi (160 MPa)
Yield (0.2%)
24 ksi (165 MPa)
13 ksi (90 MPa)
Elongation
3.5%
1.5%
Hardness (typ. Brinell)
70–105 HB
55–85 HB
Physical properties (typical)
Density
2.67 g/cc
2.79 g/cc
Electrical conductivity
~40% IACS
~27% IACS
Thermal conductivity
151 W/m·K
109 W/m·K
Thermal expansion (CTE)
21.4 µm/m·°C (20–100°C)
21.4 µm/m·°C (20–100°C)
Chemistry Limits
Percentage by weight
Silicon 6.5% – 7.5%
Iron 2.0%
Copper 0.20%
Manganese 0.10%
Magnesium 0.25% – 0.45%
Zinc 0.10%
Titanium 0.20%
Others each 0.05%, total 0.15%
Silicon 5.5% – 6.5%
Iron 1.0%
Copper 3.0% – 4.0%
Manganese 0.50%
Magnesium 0.10%
Nickel 0.35%
Zinc 1.0%
Titanium 0.25%
Others total ≤.5%
Quick “solution picker”
Need higher strength + ductility headroom (T6) and strong leak-tight potential? → A356.0-T6
Need machining efficiency + as-cast simplicity and stable production? → 319.0-F
Note: mechanical minimums are based on separately cast test bars; properties in actual castings vary with section size, solidification quality, porosity control, and heat treat practice.
Talk to us about how we can help find the right solution for your application.