Introduction
204.0 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 | 204.0 |
| 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 | 204.0 | UNS A02040 |
Related Casting Products
Physical Properties
N/A
Chemical Composition
| Element | ASTM B26/B26MEdition 05 · wt.% |
|---|---|
| Si | ≤ 0.20 |
| Fe | ≤ 0.35 |
| Cu | 4.2–5.0 |
| Mn | ≤ 0.10 |
| Mg | 0.15–0.35 |
| Ni | ≤ 0.05 |
| Zn | ≤ 0.10 |
| Ti | 0.15–0.30 |
| Sn | ≤ 0.05 |
| 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 · T4 · Recommended heat treatment
Notes
ASTM B26/B26M · Edition 05
[1] T4, T4 · 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.; ±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.
[2] T4, T4 · Recommended heat treatment: room temperature; 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).; In order to expedite testing, alloy 204.0 test specimens may be precipitation heat treated after quenching by holding at 255°F for 2 h.; No quenching required. Cool in still air outside the furnace.; ±5°C; In order to expedite testing, alloy 204.0 test specimens may be precipitation heat treated after quenching by holding at 125°C for 2 h.
Mechanical Properties
| Property | ASTM B26/B26MEdition 05 |
|---|---|
| Tensile Strength | ≥ 45.0 ksi / ≥ 310 MPa[1] |
| Yield Strength (Rp0.2) | ≥ 28.0 ksi / ≥ 195 MPa[1] |
| Elongation | ≥ 6.0 %[1] |
Notes
ASTM B26/B26M · Edition 05
[1] Tensile Strength/Yield Strength (Rp0.2)/Elongation: inch-pound; 2 in. or 4 x diameter / SI; 5 x diameter
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