Aluminum A384
AA A384 · UNS A13840 · ASTM B85 A384-F · EN AlSi11Cu3 die cast
A384 is a high-silicon, copper-bearing Al-Si-Cu die casting alloy (about 11% Si, 3–4.5% Cu; A13840, B85 A384-F) used in the as-cast F condition.
A384 tempers and conditions
A384 is supplied in one standard condition, F.
What is A384?
A384 is a high-silicon, copper-bearing Al-Si-Cu die casting alloy (about 11% Si, 3–4.5% Cu; A13840, B85 A384-F) used in the as-cast F condition. Very good fluidity and hot-tear resistance make it suited to thin-wall, complex housings, transmission cases and structural die castings, with relatively high as-cast strength and hardness. The copper content reduces corrosion resistance and decorative anodizing quality, and ductility is low (elongation about 1–3%). It is normally not heat treated and is unsuitable for fusion welding or significant forming. A384 has a density of 2.82 g/cm³ (0.102 lb/in³), heavier than 89% of aluminum grades. It melts at 516°C (961 °F). A384 has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 325 MPa (47.1 ksi) — weaker than 58% of aluminum grades. Elongation at break is 2.5% and the elastic modulus is 71 GPa (10.3 Msi).
What is A384 used for?
- Engine blocks
- Transmission cases
- Gearbox and pump housings
- Thin-wall electronics and telecom housings
- Automotive brackets and covers
- Structural die-cast enclosures
- Compressor housings
Advantages
- High service temperature — 175°C (347 °F), better than 83% of aluminum grades
Limitations
- Low electrical conductivity — 23 % IACS, worse than 97% of aluminum grades
- Poor heat conductor — 96 W/m·K (55.5 BTU/hr·ft·°F), worse than 95% of aluminum grades
- Hard to polish — 40/100, worse than 91% of aluminum grades
- Difficult to weld — 20/100, worse than 89% of aluminum grades
- Limited formability — 8/100, worse than 88% of aluminum grades
A384 properties
Typical room-temperature values; bars are the position among aluminum grades.
Physical3
A384 has a density of 2.82 g/cm³ (0.102 lb/in³), heavier than 89% of aluminum grades. It melts at 516°C (961 °F).
Mechanical14
A384 has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 325 MPa (47.1 ksi) — weaker than 58% of aluminum grades. Elongation at break is 2.5% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
A384 is rated for continuous service to 175°C (347 °F). It conducts heat at 96 W/m·K (55.5 BTU/hr·ft·°F), worse than 95% of aluminum grades. Thermal expansion is 20.9 µm/m·K (11.6 µin/in·°F).
Electrical3
A384 conducts electricity at 23 % IACS, worse than 97% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (38/100), worse than 79% of aluminum grades.
Sustainability4
Producing a kilogram of A384 takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 90%.
Manufacturability8
A384's machinability is good (60/100, worse than 51% of aluminum grades); weldability poor (20/100); formability not recommended (8/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the aluminum family
Yield strength against density for every aluminum grade FabDigit runs. A384 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A384
Is A384 easy to machine?
Machines to good finish with sharp positive-rake carbide or PCD tools and flood coolant, but ~11% Si is abrasive — expect fast edge wear and avoid deep cuts into subsurface porosity.
Can A384 be welded?
Not recommended for fusion welding (Cu content + gas porosity cause cracking); join by mechanical fastening, self-piercing rivets, or adhesive; friction-stir/laser only with qualified low-porosity vacuum castings.
Can A384 be formed, bent or molded?
Cold-chamber high-pressure die casting alloy with excellent fluidity and hot-tear resistance — ideal for thin walls (≥1.0 mm) and complex cores; not for bending, forming, or heat treatment (blistering risk).
Manufacturability
The process limits FabDigit applies to A384. Every A384 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better60 / 100 |
|---|---|
| ISO material group | N.1 |
| Cutting speed (rough / finish) | 350 / 420 m/min |
| Minimum wall | 0.5 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 8× diameter |
| Best surface (machined / polished) | Ra 0.8 / — |
| Hardenable after machining | No |
A384 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Siprimary strength/fluidity former | 10.5 – 12 | 11.2 |
| Cu | 3 – 4.5 | 3.8 |
| Fedie-casting max; reduces die soldering | ≤ 1.3 | 0.9 |
| Mn | ≤ 0.5 | 0.25 |
| Mg | ≤ 0.1 | 0.05 |
| Ni | ≤ 0.5 | 0.1 |
| Zn384.0 and B384.0 allow up to 3.0 Zn | ≤ 1 | 0.5 |
| Sn | ≤ 0.35 | |
| Tiwhen specified | ≤ 0.2 | |
| Others (each/total)others total 0.50 max | ≤ 0.5 | |
| Al | balance |
What surface finishes work on A384?
Best finished by chromate/zirconium conversion coating plus paint or powder coat; decorative anodizing is poor (dark grey mottle), while shot blasting, vibratory deburring and electroless nickel/chrome plating work well.
Surface treatments FabDigit runs on aluminum parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Conversion Coating
PVD Coating
Equivalent designations
Standards and trade names that resolve to Aluminum A384 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- A13840
- ASTM
- B85 A384-F
- EN / DIN / Werkstoff-Nr.
- AlSi11Cu3 die cast
- Also called
- 384 Aluminum
How much does A384 cost?
A384 is a budget-cost aluminum ($), cheaper than about 82% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
A384 — frequently asked
What is A384 used for?
A384 is typically used for engine blocks, transmission cases, gearbox and pump housings, thin-wall electronics and telecom housings, automotive brackets and covers and structural die-cast enclosures. In short: high-fluidity die cast.
What is the yield strength of A384?
A384 has a typical yield strength of 165 MPa (23.9 ksi) and a tensile strength of 325 MPa (47.1 ksi) — weaker than 58% of aluminum grades.
Is A384 easy to machine?
Reasonably — machinability is rated good (60/100, worse than 51% of aluminum grades). Machines to good finish with sharp positive-rake carbide or PCD tools and flood coolant, but ~11% Si is abrasive — expect fast edge wear and avoid deep cuts into subsurface porosity.
Can A384 be welded?
Not readily — weldability is rated poor (20/100). Not recommended for fusion welding (Cu content + gas porosity cause cracking); join by mechanical fastening, self-piercing rivets, or adhesive; friction-stir/laser only with qualified low-porosity vacuum castings.
What surface finishes work on A384?
Best finished by chromate/zirconium conversion coating plus paint or powder coat; decorative anodizing is poor (dark grey mottle), while shot blasting, vibratory deburring and electroless nickel/chrome plating work well.
Can A384 be formed, bent or molded?
Cold-chamber high-pressure die casting alloy with excellent fluidity and hot-tear resistance — ideal for thin walls (≥1.0 mm) and complex cores; not for bending, forming, or heat treatment (blistering risk).
What is the maximum service temperature of A384?
A384 is rated for continuous use to about 175°C (347 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does A384 cost?
A384 is a budget-cost aluminum ($), cheaper than about 82% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in A384?
Yes — A384 is available for CNC machining; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B85/B85M — Aluminum-Alloy Die Castings — ASTM International (2018)
- Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot (Pink Sheets) — The Aluminum Association (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- NADCA Product Specification Standards for Die Castings — North American Die Casting Association (2018)
- GB/T 15115 (YL113/ADC12 ) — SAC (2009)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.