Aluminum AC4D
JIS AC4D · EN AC-45300
AC4D is a JIS Al-Si-Cu-Mg casting alloy (ZL105, A355.0 / 355.0) that adds about 1–1.5 % Cu to the Al-Si-Mg base for higher heat-treated strength and hardness.
Reference datasheet — AC4D 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
AC4D tempers and conditions
AC4D is supplied in 5 conditions, soft to hard. T6 is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Lowest-cost condition for lightly loaded, dimensionally stable-enough parts where no strengthening is needed. | 100 | 170 | 2.5 | 65 HB | 43 % IACS |
Cooled from hot working and artificially aged | Choose when dimensional stability and a modest strength/hardness gain are wanted without the distortion risk of solution quenching. | 155 | 195 | 1.5 | 72 HB | 42 % IACS |
T6Default Solution heat treated and artificially aged | Standard high-strength condition: best strength/ductility balance for pressure-tight, moderately loaded castings. | 180 | 250 | 2.5 | 88 HB | 39 % IACS |
Solution heat treated and overaged (stabilized) | Use when long-term dimensional stability at elevated temperature matters more than peak room-temperature strength. | 235 | 260 | 1 | 85 HB | 41 % IACS |
T6 variant, underaged | Pick for maximum strength and hardness / best wear and machined-surface finish where very low elongation is acceptable. | 245 | 280 | 1 | 96 HB | 37 % IACS |
What is AC4D?
AC4D is a JIS Al-Si-Cu-Mg casting alloy (ZL105, A355.0 / 355.0) that adds about 1–1.5 % Cu to the Al-Si-Mg base for higher heat-treated strength and hardness. It is chosen for gravity and sand castings that need more mechanical capability than AC4C — cylinder heads, aircraft fittings and high-strength housings — with 180 MPa yield, 250 MPa tensile, 2.5 % elongation, 88 HB and 151 W/m·K. Ductility and weldability are lower than AC4C because of the copper, and service is limited to about 150 °C; use AC4C where fusion welding or corrosion resistance governs. AC4D has a density of 2.71 g/cm³ (0.0979 lb/in³), heavier than 51% of aluminum grades. It melts at 549°C (1,020 °F). AC4D has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 54% of aluminum grades. Elongation at break is 2.5% and the elastic modulus is 71 GPa (10.3 Msi).
What is AC4D used for?
- cylinder heads
- aircraft fittings
- high-strength housings
Limitations
- Limited ductility — 2.5%, worse than 83% of aluminum grades
- Limited formability — 10/100, worse than 80% of aluminum grades
- Hard to polish — 45/100, worse than 76% of aluminum grades
AC4D properties
Typical room-temperature values for AC4D-T6; bars are the position among aluminum grades.
Physical3
AC4D has a density of 2.71 g/cm³ (0.0979 lb/in³), heavier than 51% of aluminum grades. It melts at 549°C (1,020 °F).
Mechanical12
AC4D has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 54% of aluminum grades. Elongation at break is 2.5% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
AC4D 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 22.3 µm/m·K (12.4 µin/in·°F).
Electrical3
AC4D conducts electricity at 39 % IACS, better than 65% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 62% of aluminum grades.
Sustainability4
Producing a kilogram of AC4D takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 70%.
Manufacturability8
AC4D's machinability is good (62/100, better than 55% of aluminum grades); weldability fair (40/100); formability not recommended (10/100).
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. AC4D is highlighted; hover a dot for its name, or open the interactive family chart.
Working with AC4D
Is AC4D easy to machine?
Machines well in T6/T61 with sharp carbide or PCD tooling, high speed and flood coolant; eutectic Si is abrasive, so avoid HSS for production runs and expect some tool wear.
Can AC4D be welded?
Fusion welding is only fair — the 1–1.5 % Cu promotes hot cracking and reduces as-welded properties; use 4043/4145 filler for repair and re-solution + re-age if full strength is required.
Can AC4D be formed, bent or molded?
Sand and permanent-mould (gravity) casting alloy with good fluidity and pressure tightness; requires well-fed risers and controlled solidification to avoid shrinkage porosity, and Sr/Na modification plus Ti-B refinement improve ductility.
AC4D 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 |
|---|---|---|
| Sifluidity and strength | 4.5 – 5.5 | 5 |
| Custrength; lowers corrosion resistance | 1 – 1.5 | 1.25 |
| MgMg2Si precipitation hardening | 0.4 – 0.6 | 0.5 |
| Feimpurity max (sand/permanent mould) | ≤ 0.6 | |
| Mn | ≤ 0.5 | |
| Zn | ≤ 0.3 | |
| Ni | ≤ 0.2 | |
| Tigrain refinement | ≤ 0.2 | |
| Cr | ≤ 0.15 | |
| Sn | ≤ 0.05 | |
| Pb | ≤ 0.05 | |
| Al | balance |
What surface finishes work on AC4D?
Hard or sulphuric anodize is functional but dark and mottled; chromate conversion, epoxy primer/paint or impregnation for pressure tightness are the usual routes, and polishing is limited by Si particles.
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 AC4D in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- AC-45300
- Similar grades
- ZL105A355.0355.0
How much does AC4D cost?
AC4D 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.
AC4D — frequently asked
What is AC4D used for?
AC4D is typically used for cylinder heads, aircraft fittings and high-strength housings. In short: cu-Mg strengthened AC4C; higher hardness, lower ductility; pressure-tight gravity castings.
What is the yield strength of AC4D?
AC4D has a typical yield strength of 180 MPa (26.1 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 54% of aluminum grades. Strength varies by condition: see the 5 listed tempers.
Is AC4D easy to machine?
Reasonably — machinability is rated good (62/100, better than 55% of aluminum grades). Machines well in T6/T61 with sharp carbide or PCD tooling, high speed and flood coolant; eutectic Si is abrasive, so avoid HSS for production runs and expect some tool wear.
Can AC4D be welded?
With care — weldability is rated fair (40/100). Fusion welding is only fair — the 1–1.5 % Cu promotes hot cracking and reduces as-welded properties; use 4043/4145 filler for repair and re-solution + re-age if full strength is required.
What surface finishes work on AC4D?
Hard or sulphuric anodize is functional but dark and mottled; chromate conversion, epoxy primer/paint or impregnation for pressure tightness are the usual routes, and polishing is limited by Si particles.
Can AC4D be formed, bent or molded?
Sand and permanent-mould (gravity) casting alloy with good fluidity and pressure tightness; requires well-fed risers and controlled solidification to avoid shrinkage porosity, and Sr/Na modification plus Ti-B refinement improve ductility.
What is the maximum service temperature of AC4D?
AC4D 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 AC4D-T6 and AC4D-F?
T6 is the default condition — standard high-strength condition: best strength/ductility balance for pressure-tight, moderately loaded castings. F: lowest-cost condition for lightly loaded, dimensionally stable-enough parts where no strengthening is needed. Yield strength is 180 MPa in T6 versus 100 MPa in F.
How much does AC4D cost?
AC4D 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
- JIS H 5202 Aluminium alloy castings — JSA (2010)
- GB/T 1173 (ZL105 / ZAlSi5Cu1Mg) — SAC (2013)
- ASTM B26/B26M Aluminum-Alloy Sand Castings (355.0) — ASTM (2018)
- ASM Handbook Vol. 2 — Properties of Aluminum Casting Alloys — ASM International (1990)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys — ASM International (1993)
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.