C355.0 (SC51B, A33550) Cast Aluminum
C355.0 aluminum is an aluminum alloy formulated for casting. C355.0 is the Aluminum Association (AA) designation for this material. 335 is the SAE designation. And A33550 is the UNS number. Older literature may refer to this material as ASTM SC51B, but this is now discouraged.
This material originally entered the market in 1955.
The properties of C355.0 aluminum include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare C355.0 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
86 to 90
Elastic (Young's, Tensile) Modulus
70 GPa 10 x 106 psi
Elongation at Break
2.7 to 3.8 %
Fatigue Strength
76 to 84 MPa 11 to 12 x 103 psi
Poisson's Ratio
0.33
Shear Modulus
26 GPa 3.8 x 106 psi
Tensile Strength: Ultimate (UTS)
290 to 310 MPa 42 to 44 x 103 psi
Tensile Strength: Yield (Proof)
200 to 230 MPa 29 to 34 x 103 psi
Thermal Properties
Latent Heat of Fusion
470 J/g
Maximum Temperature: Mechanical
170 °C 340 °F
Melting Completion (Liquidus)
620 °C 1150 °F
Melting Onset (Solidus)
570 °C 1050 °F
Solidification (Pattern Maker's) Shrinkage
1.3 %
Specific Heat Capacity
900 J/kg-K 0.21 BTU/lb-°F
Thermal Conductivity
150 W/m-K 84 BTU/h-ft-°F
Thermal Expansion
22 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
39 % IACS
Electrical Conductivity: Equal Weight (Specific)
130 % 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)
7.5 to 9.8 MJ/m3
Resilience: Unit (Modulus of Resilience)
290 to 380 kJ/m3
Stiffness to Weight: Axial
14 points
Stiffness to Weight: Bending
51 points
Strength to Weight: Axial
30 to 32 points
Strength to Weight: Bending
36 to 37 points
Thermal Diffusivity
60 mm2/s
Thermal Shock Resistance
13 to 14 points
Alloy Composition
Among cast aluminum alloys, the composition of C355.0 aluminum is notable for containing comparatively high amounts of copper (Cu) and silicon (Si). Copper is used to improve strength. This comes at the cost of a decrease in corrosion resistance and weldability. Silicon is used to improve casting fluidity and lower melting temperature. It also has a strengthening effect.
| Al | 91.7 to 94.1 | |
| Si | 4.5 to 5.5 | |
| Cu | 1.0 to 1.5 | |
| Mg | 0.4 to 0.6 | |
| Fe | 0 to 0.2 | |
| Ti | 0 to 0.2 | |
| Mn | 0 to 0.1 | |
| Zn | 0 to 0.1 | |
| res. | 0 to 0.15 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B686: Standard Specification for Aluminum Alloy Castings, High-Strength
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
Aluminum: Properties and Physical Metallurgy, John E. Hatch (editor), 1984
ASM Specialty Handbook: Aluminum and Aluminum Alloys, J. R. Davis (editor), 1993