Introduction
705.0 is a casting grade in the Aluminum-Zinc 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 | 705.0 |
| Material Type | Aluminum Alloy |
| Sub Type | Aluminum-Zinc 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 | 705.0 | UNS A07050 |
Related Casting Products
Physical Properties
N/A
Chemical Composition
| Element | ASTM B26/B26MEdition 05 · wt.% |
|---|---|
| Si | ≤ 0.20 |
| Fe | ≤ 0.8 |
| Cu | ≤ 0.20 |
| Mn | 0.40–0.6 |
| Mg | 1.4–1.8 |
| Cr | 0.20–0.40 |
| Zn | 2.7–3.3 |
| 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 · T5 · Recommended heat treatment
| Step | Operation | Temperature / holding time | Cooling |
|---|---|---|---|
| 1 | Recommended: Precipitation heat treatment | 210 °F / 100 °C; Holding time: 8 h[1] | Still air outside furnace |
Notes
ASTM B26/B26M · Edition 05
[1] T5, T5 · 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
| Property | ASTM B26/B26MEdition 05 |
|---|---|
| Tensile Strength | ≥ 30.0 ksi / ≥ 205 MPa[1] |
| Yield Strength (Rp0.2) | ≥ 17.0 ksi / ≥ 115 MPa[2] |
| Elongation | ≥ 5.0 %[1] |
| Brinell Hardness | 65 HB[3] |
Notes
ASTM B26/B26M · Edition 05
[1] Tensile Strength/Elongation: inch-pound; 2 in. or 4 x diameter / SI; 5 x diameter
[2] Yield Strength (Rp0.2): inch-pound; 2 in. or 4 x diameter; yield-strength determination specified in contract or purchase order / SI; 5 x diameter; yield-strength determination specified in contract or purchase order
[3] Brinell Hardness: 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