Aluminum A242.0
AA A242.0 · UNS A12420
A242.0 is an Al-Cu-Ni-Mg casting alloy (ANSI/AA 2xx.x series, UNS A12420) offered in F, O, T571, T61, T75, T77 and T21, with 145 MPa yield, 214 MPa tensile, 2% elongation and 75 HB in the default condition and a 260 °C maximum service temperature.
Reference datasheet — A242.0 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 T75 condition
A242.0 tempers and conditions
A242.0 is supplied in 7 conditions, soft to hard. T75 is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Raw casting before any thermal treatment; used only as an intermediate state or for non-structural parts. | 105 | 165 | 1.5 | 65 HB | 33 % IACS |
Annealed | Choose when maximum dimensional stability and lowest residual stress matter more than strength. | 124 | 186 | 1 | 70 HB | 44 % IACS |
Annealed / partially solution treated and stabilised | Soft, highly stable condition used where machining accuracy and freedom from growth outweigh strength. | 124 | 186 | 1.5 | 70 HB | 42 % IACS |
T75Default Solution heat treated and overaged/stabilised | Standard supply condition for A242.0: balanced strength with dimensional stability and creep resistance at 200–260 °C. | 145 | 214 | 2 | 75 HB | 36 % IACS |
Solution heat treated and fully overaged | Pick for parts that run hottest and longest — lowest growth and best residual-stress relief, at reduced strength. | 159 | 207 | 2 | 75 HB | 38 % IACS |
As-cast then artificially aged | Low-distortion route: no solution treatment, good stability and hardness for cylinder heads and pistons. | 207 | 221 | 0.7 | 90 HB | 34 % IACS |
T6 variant, underaged | Highest room-temperature strength and hardness, mainly on permanent-mold castings; ductility is minimal. | 234 | 276 | 0.5 | 105 HB | 33 % IACS |
What is A242.0?
A242.0 is an Al-Cu-Ni-Mg casting alloy (ANSI/AA 2xx.x series, UNS A12420) offered in F, O, T571, T61, T75, T77 and T21, with 145 MPa yield, 214 MPa tensile, 2% elongation and 75 HB in the default condition and a 260 °C maximum service temperature. It is used, typically in T75, for engine and aerospace parts that must hold strength and dimensional stability while hot, with 140 W/m·K thermal conductivity for heat rejection. Elongation is low, corrosion resistance is limited (32/100) and fusion welding is impractical; A206.0 or 356.0-type alloys are better where ductility or weldability matters more than hot strength. A242.0 has a density of 2.81 g/cm³ (0.102 lb/in³), heavier than 86% of aluminum grades. It melts at 528°C (982 °F). A242.0 has a yield strength of 145 MPa (21 ksi) and a tensile strength of 214 MPa (31 ksi) — weaker than 68% of aluminum grades. Elongation at break is 2% and the elastic modulus is 71 GPa (10.3 Msi).
What is A242.0 used for?
- cylinder heads
- pistons
- engine covers
- aerospace elevated-temperature parts
Advantages
- High service temperature — 260°C (500 °F), better than 99% of aluminum grades
Limitations
- Needs corrosion protection — 32/100, worse than 94% of aluminum grades
- Limited ductility — 2%, worse than 87% of aluminum grades
- Difficult to weld — 22/100, worse than 83% of aluminum grades
- Hard to polish — 45/100, worse than 76% of aluminum grades
A242.0 properties
Typical room-temperature values for A242.0-T75; bars are the position among aluminum grades.
Physical3
A242.0 has a density of 2.81 g/cm³ (0.102 lb/in³), heavier than 86% of aluminum grades. It melts at 528°C (982 °F).
Mechanical11
A242.0 has a yield strength of 145 MPa (21 ksi) and a tensile strength of 214 MPa (31 ksi) — weaker than 68% of aluminum grades. Elongation at break is 2% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
A242.0 is rated for continuous service to 260°C (500 °F). It conducts heat at 140 W/m·K (80.9 BTU/hr·ft·°F), worse than 52% of aluminum grades. Thermal expansion is 22.5 µm/m·K (12.5 µin/in·°F).
Electrical3
A242.0 conducts electricity at 36 % IACS, better than 55% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is poor (32/100), worse than 94% of aluminum grades.
Sustainability4
Producing a kilogram of A242.0 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 25%.
Manufacturability7
A242.0's machinability is good (62/100, better than 55% of aluminum grades); weldability poor (22/100).
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. A242.0 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with A242.0
Is A242.0 easy to machine?
Machines well with sharp carbide tooling and high speeds; Al₃Ni and Al₂Cu particles are abrasive, so use PCD for long runs and flood coolant to avoid built-up edge.
Can A242.0 be welded?
Essentially non-weldable by fusion for structural joints — high Cu content causes hot cracking; repair only by qualified foundry weld procedures followed by re-heat treatment.
Can A242.0 be formed, bent or molded?
Sand and permanent-mold casting only; fluidity is fair and the alloy is hot-tear sensitive, so use generous fillets, chills and directional-solidification gating.
A242.0 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 |
|---|---|---|
| Siimpurity limit | ≤ 0.6 | 0.3 |
| Feimpurity limit | ≤ 0.8 | 0.4 |
| Cuprimary strengthener (Al₂Cu) | 3.7 – 4.5 | 4.1 |
| Mn | ≤ 0.1 | 0.05 |
| Mgwith Cu forms S-phase | 1.2 – 1.8 | 1.5 |
| Crdispersoid former, thermal stability | 0.15 – 0.25 | 0.2 |
| NiAl₃Ni for hot strength | 1.8 – 2.3 | 2 |
| Zn | ≤ 0.1 | 0.03 |
| Tigrain refiner | 0.07 – 0.2 | 0.12 |
| Others (each) | ≤ 0.05 | |
| Others (total) | ≤ 0.15 | |
| Al | balance |
What surface finishes work on A242.0?
Anodizing gives dark, non-decorative films; specify chromate conversion plus primer/paint for corrosion protection, or hard anodize/plating for wear surfaces.
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 A242.0 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- A12420
How much does A242.0 cost?
A242.0 is a premium-cost aluminum ($$$), cheaper than about 51% 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.
A242.0 — frequently asked
What is A242.0 used for?
A242.0 is typically used for cylinder heads, pistons, engine covers and aerospace elevated-temperature parts. In short: best hot-strength cast aluminum; 260 °C service capability; low ductility, not weldable.
What is the yield strength of A242.0?
A242.0 has a typical yield strength of 145 MPa (21 ksi) and a tensile strength of 214 MPa (31 ksi) — weaker than 68% of aluminum grades. Strength varies by condition: see the 7 listed tempers.
Is A242.0 easy to machine?
Reasonably — machinability is rated good (62/100, better than 55% of aluminum grades). Machines well with sharp carbide tooling and high speeds; Al₃Ni and Al₂Cu particles are abrasive, so use PCD for long runs and flood coolant to avoid built-up edge.
Can A242.0 be welded?
Not readily — weldability is rated poor (22/100). Essentially non-weldable by fusion for structural joints — high Cu content causes hot cracking; repair only by qualified foundry weld procedures followed by re-heat treatment.
What surface finishes work on A242.0?
Anodizing gives dark, non-decorative films; specify chromate conversion plus primer/paint for corrosion protection, or hard anodize/plating for wear surfaces.
Can A242.0 be formed, bent or molded?
Sand and permanent-mold casting only; fluidity is fair and the alloy is hot-tear sensitive, so use generous fillets, chills and directional-solidification gating.
What is the maximum service temperature of A242.0?
A242.0 is rated for continuous use to about 260°C (500 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between A242.0-T75 and A242.0-T61?
T75 is the default condition — standard supply condition for A242.0: balanced strength with dimensional stability and creep resistance at 200–260 °C. T61: highest room-temperature strength and hardness, mainly on permanent-mold castings; ductility is minimal. Yield strength is 145 MPa in T75 versus 234 MPa in T61.
How much does A242.0 cost?
A242.0 is a premium-cost aluminum ($$$), cheaper than about 51% 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
- Registration Record of International Alloy Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot (Pink Sheets) — The Aluminum Association (2019)
- 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 and Special-Purpose Materials — ASM International (1990)
- ASM Specialty Handbook — Aluminum and Aluminum Alloys — ASM International (1993)
- ASM Handbook Vol. 15 — Casting — ASM International (2008)
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.