Introduction
242.0 is a casting grade in the Aluminum-Copper Alloy family, specified in ASTM B26/B26M. The specification defines its chemical composition and mechanical requirements for the applicable sand-casting tempers. Casting process options include Sand Casting, subject to the applicable specification and component requirements.
| Field | Value |
|---|---|
| Designation | 242.0 |
| Material Type | Aluminum Alloy |
| Sub Type | Aluminum-Copper Alloy |
| Product Form | casting |
Manufacturing Process
Sand Casting
Equivalent Grades
N/A
Similar Materials
N/A
Reference Standards
| Standard | Standard Title | Edition | Specification | Identifier |
|---|---|---|---|---|
| ASTM B26/B26M | Standard Specification for Aluminum-Alloy Sand Castings | 05 | 242.0 | UNS A02420 |
Related Casting Products
Physical Properties
N/A
Chemical Composition
| Element | ASTM B26/B26MEdition 05 · wt.% |
|---|---|
| Si | ≤ 0.7 |
| Fe | ≤ 1.0 |
| Cu | 3.7–4.5 |
| Mn | ≤ 0.35 |
| Mg | 1.2–1.8 |
| Cr | ≤ 0.25 |
| Ni | 1.7–2.3 |
| Zn | ≤ 0.35 |
| Ti | ≤ 0.25 |
| Al | remainder |
Notes
ASTM B26/B26M · Edition 05
[1] Chemical composition: Other elements, each: ≤ 0.05 wt.%
[2] Chemical composition: Other elements, total: ≤ 0.15 wt.%
Heat Treatment
ASTM B26/B26M–05 · Sand Casting · O · Recommended heat treatment
| Step | Operation | Temperature / holding time | Cooling |
|---|---|---|---|
| 1 | Recommended: Annealing | 650 °F / 345 °C; Holding time: 3 h[1] | Still air outside furnace |
ASTM B26/B26M–05 · Sand Casting · T61 · Recommended heat treatment
Notes
ASTM B26/B26M · Edition 05
[1] O, O · Recommended heat treatment: Source: ASTM B917/B917M–25 (Recommended; when specified by the material specification or purchase order).; ±10°F; Use suitable metal-temperature measurement; sections/microstructure affect soak time selection (7.2).; No quenching required. Cool in still air outside the furnace.; Footnote H (footnotes), O — inch-pound: Solution treatment temperature of 1010°F may be used (to obtain higher solubility) provided no portion of the heat treat oven exceeds 1020°F.; ±5°C; Footnote H (footnotes), O — SI: Solution treatment temperature of 545°C may be used (to obtain higher solubility) provided no portion of the heat treat oven exceeds 550°C.
[2] T61, T61 · Recommended heat treatment: Source: ASTM B917/B917M–25 (Recommended; when specified by the material specification or purchase order).; ±10°F; Use suitable metal-temperature measurement; sections/microstructure affect soak time selection (7.2).; Quench in water at 150 to 212°F except as noted.; Time at solution temperature may be increased for section thickness over 1 in.; Quenching is accomplished by air blast.; ±5°C; Quench in water at 65 to 100°C except as noted.; Time at solution temperature may be increased for section thickness over 25 mm.
[3] T61, T61 · Recommended heat treatment: Source: ASTM B917/B917M–25 (Recommended; when specified by the material specification or purchase order).; ±10°F; Use suitable metal-temperature measurement; sections/microstructure affect soak time selection (7.2).; No quenching required. Cool in still air outside the furnace.; ±5°C
Mechanical Properties
Conditions are not identical. Compare each stated condition and applicability separately.
| Property | ASTM B26/B26MEdition 05O | ASTM B26/B26MEdition 05T61 |
|---|---|---|
| Yield Strength (Rp0.2) | Not Applicable Not Applicable | ≥ 20.0 ksi / ≥ 140 MPa[1] |
| Elongation | Not Applicable Not Applicable | Not Applicable Not Applicable |
| Tensile Strength | ≥ 23.0 ksi / ≥ 160 MPa[2] | ≥ 32.0 ksi / ≥ 220 MPa[1] |
| Brinell Hardness | 70 HB[3] | 105 HB[4] |
Notes
ASTM B26/B26M · Edition 05
[1] Yield Strength (Rp0.2)/Tensile Strength; T61: inch-pound; 2 in. or 4 x diameter / SI; 5 x diameter
[2] Tensile Strength; O: inch-pound; 2 in. or 4 x diameter / SI; 5 x diameter
[3] Brinell Hardness; O: inch-pound; 2 in. or 4 x diameter; 500 kgf; 10 mm; Typical hardness is for information only, not required for acceptance / SI; 5 x diameter; Typical hardness is for information only, not required for acceptance
[4] Brinell Hardness; T61: inch-pound; 2 in. or 4 x diameter; 500 kgf; 10 mm; Typical hardness is for information only, not required for acceptance / SI; 5 x diameter; Typical hardness is for information only, not required for acceptance
Welding Conditions
N/A
Applications
At the material-family level, typical applications include custom, shaped aluminum sand-cast components for non-aerospace use. ASTM B26/B26M excludes aerospace applications; suitability of this grade must be checked against the component requirements and specified temper.
Last Updated: October 13, 2026