Aluminum 319
AA 319 · UNS A03190 · also SC64D
319 is an Al-Si-Cu casting alloy (about 6 % Si, 3.5 % Cu) from the ANSI/AA 3xx.x family, poured by sand, permanent-mould and low-pressure casting and supplied as-cast or in T5, T6 and T7.
319 tempers and conditions
319 is supplied in 3 conditions, soft to hard.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution heat treated and overaged (stabilized) | Overaged for maximum dimensional and thermal stability (e.g. cylinder heads, fixtures) — gives up some strength versus T6 in exchange for stability and ductility. | 150 | 215 | 2.5 | 75 HB | 30 % IACS |
Solution heat treated and artificially aged | Highest strength condition; choose for loaded structural or pressure castings where full heat-treat cost and some distortion are acceptable. | 165 | 250 | 2 | 80 HB | 26 % IACS |
Cooled from hot working and artificially aged | Cheap ageing-only treatment: raises yield strength and improves dimensional stability with no solution-treatment distortion, at the cost of ductility. | 179 | 207 | 1.5 | 80 HB | 28 % IACS |
What is 319?
319 is an Al-Si-Cu casting alloy (about 6 % Si, 3.5 % Cu) from the ANSI/AA 3xx.x family, poured by sand, permanent-mould and low-pressure casting and supplied as-cast or in T5, T6 and T7. Engineers select it for good castability and hot-tear resistance combined with heat-treatable strength, useful elevated-temperature strength and free machining from the copper, in engine blocks, cylinder heads, oil pans, pump bodies and general housings. The copper lowers corrosion resistance, elongation and anodized appearance compared with copper-free 356/A356, which is the usual alternative. Scrap tolerance is high and the alloy is often supplied as secondary (recycled) ingot. 319 has a density of 2.79 g/cm³ (0.101 lb/in³), heavier than 77% of aluminum grades. It melts at 521°C (970 °F). 319 has a yield strength of 124 MPa (18 ksi) and a tensile strength of 186 MPa (27 ksi) — weaker than 76% of aluminum grades. Elongation at break is 2% and the elastic modulus is 74 GPa (10.7 Msi).
What is 319 used for?
- Engine crankcases
- Manifolds
- Cylinder heads
Advantages
- High service temperature — 200°C (392 °F), better than 90% of aluminum grades
- Easy to machine — 72/100, better than 80% of aluminum grades
Limitations
- Limited formability — 5/100, worse than 94% of aluminum grades
- Hard to polish — 40/100, worse than 91% of aluminum grades
- Poor heat conductor — 109 W/m·K (63 BTU/hr·ft·°F), worse than 90% of aluminum grades
- Limited ductility — 2%, worse than 87% of aluminum grades
- Low electrical conductivity — 27 % IACS, worse than 86% of aluminum grades
319 properties
Typical room-temperature values; bars are the position among aluminum grades.
Physical3
319 has a density of 2.79 g/cm³ (0.101 lb/in³), heavier than 77% of aluminum grades. It melts at 521°C (970 °F).
Mechanical12
319 has a yield strength of 124 MPa (18 ksi) and a tensile strength of 186 MPa (27 ksi) — weaker than 76% of aluminum grades. Elongation at break is 2% and the elastic modulus is 74 GPa (10.7 Msi).
Thermal6
319 is rated for continuous service to 200°C (392 °F). It conducts heat at 109 W/m·K (63 BTU/hr·ft·°F), worse than 90% of aluminum grades. Thermal expansion is 21.5 µm/m·K (11.9 µin/in·°F).
Electrical3
319 conducts electricity at 27 % IACS, worse than 86% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (35/100), worse than 85% of aluminum grades.
Sustainability4
Producing a kilogram of 319 takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 75%.
Manufacturability8
319's machinability is very good (72/100, better than 80% of aluminum grades); weldability good (55/100); formability not recommended (5/100).
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. 319 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 319
Is 319 easy to machine?
One of the better-machining cast aluminium alloys — Cu-rich phases break chips well; use carbide or PCD tooling because of the hard primary/eutectic Si, and expect tool wear higher than in 6061.
Can 319 be welded?
Weldable with 4145 (or 4047) filler; the 3–4 % Cu increases hot-cracking sensitivity, so preheat, keep heat input low, and re-heat-treat after welding on T5/T6 parts.
Can 319 be formed, bent or molded?
Casting alloy only — excellent fluidity and low hot-tear tendency for sand, permanent-mould and low-pressure casting of thin, complex sections; grain-refine and Sr/Na modify the eutectic for best properties.
Manufacturability
The process limits FabDigit applies to 319. Every 319 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better72 / 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 |
319 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 |
|---|---|---|
| Si | 5.5 – 6.5 | 6 |
| Cu | 3 – 4 | 3.5 |
| Fe319.0 max 1.0 %; A319.0/B319.0 also 1.0 %, die-cast variants higher | ≤ 1 | 0.6 |
| Mn | ≤ 0.5 | 0.25 |
| MgB319.0 raises Mg to 0.10–0.50 % for higher strength | ≤ 0.1 | 0.05 |
| Ni | ≤ 0.35 | |
| ZnA319.0 allows up to 3.0 % Zn | ≤ 1 | 0.3 |
| Ti | ≤ 0.25 | 0.12 |
| Others (each)total others 0.15 % max | ≤ 0.05 | |
| Al | balance |
What surface finishes work on 319?
Painting, powder coating or chromate/chrome-free conversion coating are preferred; decorative anodizing gives a dark, blotchy film due to high Si + Cu, and impregnation is often needed to seal porosity before plating.
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 319 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- A03190
- Trade names
- SC64D
How much does 319 cost?
319 is a budget-cost aluminum ($), cheaper than about 83% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
319 — frequently asked
What is 319 used for?
319 is typically used for engine crankcases, manifolds and cylinder heads. In short: cu-bearing sand cast.
What is the yield strength of 319?
319 has a typical yield strength of 124 MPa (18 ksi) and a tensile strength of 186 MPa (27 ksi) — weaker than 76% of aluminum grades. Strength varies by condition: see the 3 listed tempers.
Is 319 easy to machine?
Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). One of the better-machining cast aluminium alloys — Cu-rich phases break chips well; use carbide or PCD tooling because of the hard primary/eutectic Si, and expect tool wear higher than in 6061.
Can 319 be welded?
Yes — weldability is rated good (55/100). Weldable with 4145 (or 4047) filler; the 3–4 % Cu increases hot-cracking sensitivity, so preheat, keep heat input low, and re-heat-treat after welding on T5/T6 parts.
What surface finishes work on 319?
Painting, powder coating or chromate/chrome-free conversion coating are preferred; decorative anodizing gives a dark, blotchy film due to high Si + Cu, and impregnation is often needed to seal porosity before plating.
Can 319 be formed, bent or molded?
Casting alloy only — excellent fluidity and low hot-tear tendency for sand, permanent-mould and low-pressure casting of thin, complex sections; grain-refine and Sr/Na modify the eutectic for best properties.
What is the maximum service temperature of 319?
319 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 319 cost?
319 is a budget-cost aluminum ($), cheaper than about 83% 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 319?
Yes — 319 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
- Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot (Pink Sheets) — The Aluminum Association (2018)
- ASTM B26/B26M — Aluminum-Alloy Sand Castings — ASTM International (2018)
- ASTM B108/B108M — Aluminum-Alloy Permanent Mold Castings — ASTM International (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys — ASM International (1993)
- GB/T 1173 (comparable ZL107) — SAC (2013)
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.