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4004 (BAlSi-7, AlSi10Mg1.5) Aluminum

4004 aluminum is a 4000-series aluminum alloy. The main alloying addition is silicon. Cited properties are appropriate for the as-fabricated (no temper or treatment) condition. 4004 is the Aluminum Association (AA) designation for this material. In European standards, it will be given as EN AW-4004. BAlSi-7 is the AWS designation. Additionally, the EN chemical designation is AlSi10Mg1,5. And the UNS number is A94004.

It originally received its standard designation in 1971.

The graph bars on the material properties cards below compare 4004 aluminum to: 4000-series alloys (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

Elastic (Young's, Tensile) Modulus

71 GPa 10 x 106 psi

Elongation at Break

2.4 %

Fatigue Strength

42 MPa 6.1 x 103 psi

Poisson's Ratio


Shear Modulus

27 GPa 3.9 x 106 psi

Shear Strength

63 MPa 9.1 x 103 psi

Tensile Strength: Ultimate (UTS)

110 MPa 16 x 103 psi

Tensile Strength: Yield (Proof)

60 MPa 8.7 x 103 psi

Thermal Properties

Brazing Temperature

590 to 600 °C 1090 to 1120 °F

Latent Heat of Fusion

540 J/g

Maximum Temperature: Mechanical

160 °C 320 °F

Melting Completion (Liquidus)

600 °C 1100 °F

Melting Onset (Solidus)

560 °C 1040 °F

Specific Heat Capacity

910 J/kg-K 0.22 BTU/lb-°F

Thermal Conductivity

130 W/m-K 78 BTU/h-ft-°F

Thermal Expansion

22 µm/m-K

Electrical Properties

Electrical Conductivity: Equal Volume

33 % IACS

Electrical Conductivity: Equal Weight (Specific)

120 % IACS

Otherwise Unclassified Properties

Base Metal Price

9.5 % relative


2.6 g/cm3 160 lb/ft3

Embodied Carbon

8.0 kg CO2/kg material

Embodied Energy

150 MJ/kg 63 x 103 BTU/lb

Embodied Water

1070 L/kg 130 gal/lb

Common Calculations

Resilience: Ultimate (Unit Rupture Work)

2.3 MJ/m3

Resilience: Unit (Modulus of Resilience)

25 kJ/m3

Stiffness to Weight: Axial

15 points

Stiffness to Weight: Bending

54 points

Strength to Weight: Axial

12 points

Strength to Weight: Bending

20 points

Thermal Diffusivity

58 mm2/s

Thermal Shock Resistance

5.1 points

Alloy Composition

Among wrought aluminum alloys, the composition of 4004 aluminum is notable for containing a comparatively high amount of silicon (Si). Silicon is used to increase strength at the expense of ductility. It also lowers the melting temperature and raises the fluidity of the alloy.

Aluminum (Al) 86 to 90
Silicon (Si) 9.0 to 10.5
Magnesium (Mg) 1.0 to 2.0
Iron (Fe) 0 to 0.8
Copper (Cu) 0 to 0.25
Zinc (Zn) 0 to 0.2
Manganese (Mn) 0 to 0.1
Residuals 0 to 0.15

All values are % weight. Ranges represent what is permitted under applicable standards.

Followup Questions

Similar Alloys

Further Reading

AWS A5.8: Specification for Filler Metals for Brazing and Braze Welding

EN 573-3: Aluminium and aluminium alloys. Chemical composition and form of wrought products. Chemical composition and form of products

Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, ASM Handbook vol. 2, ASM International, 1993