Aluminum AL4
AL4 is an AlSi9Mg heat-treatable casting alloy to GOST 1583, equivalent to ANSI/AA 356.0, available in F, T1, T4, T5, T6 and T7.
Reference datasheet — AL4 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the T6 condition
AL4 tempers and conditions
AL4 is supplied in 6 conditions, soft to hard. T6 is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Cheapest condition for lightly loaded, dimensionally stable housings where strength is not critical. | 90 | 165 | 3 | 55 HB | 43 % IACS |
Solution heat treated and naturally aged | Choose when maximum ductility and impact toughness matter more than yield strength (e.g. crash-loaded brackets). | 110 | 205 | 8 | 60 HB | 37 % IACS |
Cooled from hot working and naturally aged | Simple low-cost ageing that raises strength and stabilises dimensions without a quench, so distortion is minimal. | 140 | 205 | 2 | 70 HB | 41 % IACS |
Cooled from hot working and artificially aged | Low-temperature ageing used mainly to relieve casting stresses and stabilise dimensions with a modest strength gain. | 140 | 180 | 2 | 60 HB | 43 % IACS |
Solution heat treated and overaged (stabilized) | Overaged for dimensional stability and service above ~150 °C, trading some strength for toughness and stability. | 160 | 220 | 5 | 70 HB | 40 % IACS |
T6Default Solution heat treated and artificially aged | Standard structural condition: best combination of strength, fatigue life and acceptable ductility for loaded castings. | 180 | 240 | 4 | 75 HB | 39 % IACS |
What is AL4?
AL4 is an AlSi9Mg heat-treatable casting alloy to GOST 1583, equivalent to ANSI/AA 356.0, available in F, T1, T4, T5, T6 and T7. In the default condition it provides 180 MPa yield, 240 MPa tensile, 4% elongation and 75 HB, with 151 W/m·K thermal conductivity and 39% IACS — the highest conductivity in this group. Engineers use it for pressure-tight, weldable structural castings in sand, permanent-mold and low-pressure processes, where Mg-based T6 strengthening replaces copper. Service is limited to 150 °C and strength is well below the Al-Cu alloys A201.0 and A206.0, which are the alternatives when higher load capacity is needed. AL4 has a density of 2.68 g/cm³ (0.0968 lb/in³), lighter than 72% of aluminum grades. It melts at 557°C (1,035 °F). AL4 has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 54% of aluminum grades. Elongation at break is 4% and the elastic modulus is 72.4 GPa (10.5 Msi).
What is AL4 used for?
- Engine housings
- Gearbox casings
- Pump and valve bodies
- Intake manifolds
- Wheels
- Aircraft and structural fittings
- Electronics and heat-sink housings
Limitations
- Hard to polish — 45/100, worse than 76% of aluminum grades
AL4 properties
Typical room-temperature values for AL4-T6; bars are the position among aluminum grades.
Physical3
AL4 has a density of 2.68 g/cm³ (0.0968 lb/in³), lighter than 72% of aluminum grades. It melts at 557°C (1,035 °F).
Mechanical13
AL4 has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 54% of aluminum grades. Elongation at break is 4% and the elastic modulus is 72.4 GPa (10.5 Msi).
Thermal6
AL4 is rated for continuous service to 150°C (302 °F). It conducts heat at 151 W/m·K (87.2 BTU/hr·ft·°F), better than 63% of aluminum grades. Thermal expansion is 21.5 µm/m·K (11.9 µin/in·°F).
Electrical3
AL4 conducts electricity at 39 % IACS, better than 65% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), better than 67% of aluminum grades.
Sustainability4
Producing a kilogram of AL4 takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 55%.
Manufacturability8
AL4's machinability is good (58/100, worse than 54% of aluminum grades); weldability very good (80/100); formability not recommended (12/100).
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. AL4 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with AL4
Is AL4 easy to machine?
Machines cleanly in T6 with PCD or coated-carbide tools and high speeds; free silicon abrades HSS quickly, so use flood coolant and sharp positive-rake geometry.
Can AL4 be welded?
Readily TIG/MIG welded with ER4043 (or ER4047) filler; re-solution treat and age locally welded structural parts, and preheat/clean thoroughly to avoid porosity.
Can AL4 be formed, bent or molded?
Excellent fluidity and low hot-tearing tendency for sand, permanent-mould and low-pressure casting; Sr/Na modification plus Ti-B grain refinement and directional solidification give best properties.
AL4 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 |
|---|---|---|
| Sieutectic-forming element; Sr or Na modification usual | 8 – 10.5 | 9 |
| MgMg2Si precipitation hardening | 0.17 – 0.3 | 0.25 |
| Mnneutralises Fe needles | 0.2 – 0.5 | 0.35 |
| Felower limit (≈0.6 max) applies to sand/permanent-mould castings | ≤ 1 | 0.5 |
| Cuimpurity | ≤ 0.3 | |
| Znimpurity | ≤ 0.3 | |
| Tigrain refinement (Al-Ti-B) | ≤ 0.15 | 0.1 |
| Beoptional, restricts Mg oxidation | ≤ 0.1 | |
| Al | balance |
What surface finishes work on AL4?
Takes hard/protective anodising and chromate conversion well but the finish is grey and mottled; for cosmetic parts use powder coat or paint, and shot blast plus impregnation for pressure-tight housings.
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).
Organic Coating
Equivalent designations
Standards and trade names that resolve to Aluminum AL4 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- 356.0
How much does AL4 cost?
AL4 is a standard-cost aluminum ($$), cheaper than about 71% 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.
AL4 — frequently asked
What is AL4 used for?
AL4 is typically used for engine housings, gearbox casings, pump and valve bodies, intake manifolds, wheels and aircraft and structural fittings. In short: weldable Al-Si-Mg workhorse; best thermal conductivity here; pressure-tight T6 castings.
What is the yield strength of AL4?
AL4 has a typical yield strength of 180 MPa (26.1 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 54% of aluminum grades. Strength varies by condition: see the 6 listed tempers.
Is AL4 easy to machine?
Reasonably — machinability is rated good (58/100, worse than 54% of aluminum grades). Machines cleanly in T6 with PCD or coated-carbide tools and high speeds; free silicon abrades HSS quickly, so use flood coolant and sharp positive-rake geometry.
Can AL4 be welded?
Yes — weldability is rated very good (80/100). Readily TIG/MIG welded with ER4043 (or ER4047) filler; re-solution treat and age locally welded structural parts, and preheat/clean thoroughly to avoid porosity.
What surface finishes work on AL4?
Takes hard/protective anodising and chromate conversion well but the finish is grey and mottled; for cosmetic parts use powder coat or paint, and shot blast plus impregnation for pressure-tight housings.
Can AL4 be formed, bent or molded?
Excellent fluidity and low hot-tearing tendency for sand, permanent-mould and low-pressure casting; Sr/Na modification plus Ti-B grain refinement and directional solidification give best properties.
What is the maximum service temperature of AL4?
AL4 is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between AL4-T6 and AL4-F?
T6 is the default condition — standard structural condition: best combination of strength, fatigue life and acceptable ductility for loaded castings. F: cheapest condition for lightly loaded, dimensionally stable housings where strength is not critical. Yield strength is 180 MPa in T6 versus 90 MPa in F.
How much does AL4 cost?
AL4 is a standard-cost aluminum ($$), cheaper than about 71% 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.
Sources
- ГОСТ 1583-93 Сплавы алюминиевые литейные (АК9ч / АЛ4) — Межгосударственный совет по стандартизации (1993)
- ASTM B26/B26M — Aluminum-Alloy Sand Castings (356.0) — ASTM International (2018)
- GB/T 1173 (ZL101A) (2013)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- Aluminum Association Pink Sheets — Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot — The Aluminum Association (2018)
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.