355.0 (SC51A, A03550) Cast Aluminum
355.0 aluminum is an aluminum alloy formulated for casting. 355.0 is the Aluminum Association (AA) designation for this material. A03550 is the UNS number. Additionally, the SAE designation is 322. The British Standard (BS) designation is LM16. And the AFNOR (French) designation is A-S4UG. Older literature may refer to this material as ASTM SC51A, but this is now discouraged.
This material originally entered the market in 1930.
The properties of 355.0 aluminum include three common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare 355.0 aluminum to: ANSI/AA cast aluminums (top), all aluminum alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Brinell Hardness
72 to 83
Elastic (Young's, Tensile) Modulus
71 GPa 10 x 106 psi
Elongation at Break
1.5 to 2.6 %
Fatigue Strength
55 to 70 MPa 8.0 to 10 x 103 psi
Poisson's Ratio
0.33
Shear Modulus
27 GPa 3.9 x 106 psi
Shear Strength
150 to 240 MPa 22 to 35 x 103 psi
Tensile Strength: Ultimate (UTS)
200 to 260 MPa 29 to 38 x 103 psi
Tensile Strength: Yield (Proof)
150 to 190 MPa 21 to 27 x 103 psi
Thermal Properties
Latent Heat of Fusion
470 J/g
Maximum Temperature: Mechanical
180 °C 350 °F
Melting Completion (Liquidus)
620 °C 1150 °F
Melting Onset (Solidus)
560 °C 1050 °F
Solidification (Pattern Maker's) Shrinkage
1.3 %
Specific Heat Capacity
890 J/kg-K 0.21 BTU/lb-°F
Thermal Conductivity
150 to 170 W/m-K 85 to 97 BTU/h-ft-°F
Thermal Expansion
22 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
38 to 43 % IACS
Electrical Conductivity: Equal Weight (Specific)
120 to 140 % IACS
Otherwise Unclassified Properties
Base Metal Price
9.5 % relative
Density
2.7 g/cm3 170 lb/ft3
Embodied Carbon
8.0 kg CO2/kg material
Embodied Energy
150 MJ/kg 64 x 103 BTU/lb
Embodied Water
1120 L/kg 130 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
2.7 to 5.9 MJ/m3
Resilience: Unit (Modulus of Resilience)
150 to 250 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
51 points
Strength to Weight: Axial
20 to 27 points
Strength to Weight: Bending
28 to 33 points
Thermal Diffusivity
60 to 69 mm2/s
Thermal Shock Resistance
9.1 to 12 points
Alloy Composition
Among cast aluminum alloys, the composition of 355.0 aluminum is notable for including chromium (Cr). Chromium is used to limit grain growth during hot working or heat treatment, which improves ductility and toughness. Chromium also reduces the alloy's susceptibility to stress corrosion cracking. If the alloy is anodized, the presence of chromium will tend to add a yellow tint to the film.
| Al | 90.3 to 94.1 | |
| Si | 4.5 to 5.5 | |
| Cu | 1.0 to 1.5 | |
| Mg | 0.4 to 0.6 | |
| Fe | 0 to 0.6 | |
| Mn | 0 to 0.5 | |
| Zn | 0 to 0.35 | |
| Cr | 0 to 0.25 | |
| Ti | 0 to 0.25 | |
| res. | 0 to 0.15 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B618: Standard Specification for Aluminum-Alloy Investment Castings
ASTM B108: Standard Specification for Aluminum-Alloy Permanent Mold Castings
ASTM B26: Standard Specification for Aluminum-Alloy Sand Castings
Handbook of Aluminum Bonding Technology and Data, J. D. Minford, 1993
ASM Specialty Handbook: Aluminum and Aluminum Alloys, J. R. Davis (editor), 1993