Aluminum 7072 · temper
Aluminum 7072-O
Properties of the O condition, compared with the other 7072 tempers.
Standard stocked condition for 7072 sheet, finstock and clad veneer — maximum formability and sacrificial protection, essentially no load-carrying capability.
What is 7072-O?
7072-O is 7072 in the O temper — standard stocked condition for 7072 sheet, finstock and clad veneer — maximum formability and sacrificial protection, essentially no load-carrying capability. 7072-O has a yield strength of 21 MPa (3.05 ksi) and a tensile strength of 55 MPa (7.98 ksi) — weaker than 99% of aluminum grades. Elongation at break is 32% and the elastic modulus is 69 GPa (10 Msi). 7072-O has a density of 2.72 g/cm³ (0.0983 lb/in³), heavier than 57% of aluminum grades. It melts at 640°C (1,184 °F).
Advantages
- Ductile — tolerates forming and impact — 32%, better than 97% of aluminum grades
- Forms and bends easily — 95/100, better than 96% of aluminum grades
- Conducts heat well — 227 W/m·K (131.2 BTU/hr·ft·°F), better than 95% of aluminum grades
- High electrical conductivity — 60 % IACS, better than 95% of aluminum grades
- High service temperature — 200°C (392 °F), better than 90% of aluminum grades
Limitations
- Low strength — 21 MPa (3.05 ksi), worse than 99% of aluminum grades
- Difficult to machine — 25/100, worse than 96% of aluminum grades
- Hard to polish — 45/100, worse than 76% of aluminum grades
7072-O properties
Typical room-temperature values for 7072-O — 11 properties are specific to this condition; the rest are grade-level values shared by every 7072 temper. Each bar shows where the value sits among the aluminum grades in FabDigit's library — further right is higher.
Physical3
7072-O has a density of 2.72 g/cm³ (0.0983 lb/in³), heavier than 57% of aluminum grades. It melts at 640°C (1,184 °F).
Mechanical10
7072-O has a yield strength of 21 MPa (3.05 ksi) and a tensile strength of 55 MPa (7.98 ksi) — weaker than 99% of aluminum grades. Elongation at break is 32% and the elastic modulus is 69 GPa (10 Msi).
Thermal6
7072-O is rated for continuous service to 200°C (392 °F). It conducts heat at 227 W/m·K (131.2 BTU/hr·ft·°F), better than 95% of aluminum grades. Thermal expansion is 23.6 µm/m·K (13.1 µin/in·°F).
Electrical3
7072-O conducts electricity at 60 % IACS, better than 95% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is very good (72/100), better than 83% of aluminum grades.
Sustainability4
Producing a kilogram of 7072-O takes about 200 MJ of energy and emits 13 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 20%.
Manufacturability7
7072-O's machinability is poor (25/100, worse than 96% of aluminum grades); weldability very good (80/100); formability excellent (95/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 7072 tempers and conditions
7072 is also supplied in 7 other conditions. The full side-by-side table is on the 7072 overview.
- H14Most common work-hardened condition for 7072 heat-exchanger fin stock needing collapse resistance during fin forming.95 MPa yield · 32 HB
- OStandard stocked condition for 7072 sheet, finstock and clad veneer — maximum formability and sacrificial protection, essentially no load-carrying capability.21 MPa yield · 20 HB
Working with 7072-O
Is 7072 easy to machine?
Very soft and gummy — use sharp polished high-rake tools, high speed and flood lubricant to avoid built-up edge; parts are seldom machined since 7072 is a thin cladding or fin stock.
Can 7072 be welded?
Readily GTAW/GMAW/resistance welded and vacuum/flux brazed; on Alclad products keep heat input low so Zn diffusion into the core does not destroy the cathodic protection.
Can 7072 be formed, bent or molded?
Excellent cold formability in O temper — deep drawing, fin corrugation and roll bonding are routine; H1x tempers trade ductility for fin stiffness.
What surface finishes work on 7072?
Chromate/no-rinse conversion coating or clear anodize is typical; decorative anodizing looks duller than 1xxx and heavy caustic etching removes the thin sacrificial layer.
7072 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 |
|---|---|---|
| Znsacrificial anode element | 0.8 – 1.3 | 1 |
| Si+Fecombined limit per AA registration | ≤ 0.7 | — |
| Cu | ≤ 0.1 | — |
| Mn | ≤ 0.1 | — |
| Mg | ≤ 0.1 | — |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Alremainder, 99.0 % min basis | balance | — |
7072-O — frequently asked
What is 7072-O used for?
7072-O is typically used for alclad sacrificial surface layers, heat-exchanger finstock, brazing sheet cladding, tube cladding for condensers, corrugated radiator and condenser fins and automotive heat-exchanger strip. In short: cladding alloy for 2xxx/7xxx.
What is the yield strength of 7072-O?
7072-O has a typical yield strength of 21 MPa (3.05 ksi) and a tensile strength of 55 MPa (7.98 ksi) — weaker than 99% of aluminum grades. Strength varies by condition: see the 8 listed tempers.
Is 7072-O easy to machine?
Not especially — machinability is rated poor (25/100, worse than 96% of aluminum grades). Very soft and gummy — use sharp polished high-rake tools, high speed and flood lubricant to avoid built-up edge; parts are seldom machined since 7072 is a thin cladding or fin stock.
Can 7072-O be welded?
Yes — weldability is rated very good (80/100). Readily GTAW/GMAW/resistance welded and vacuum/flux brazed; on Alclad products keep heat input low so Zn diffusion into the core does not destroy the cathodic protection.
What surface finishes work on 7072-O?
Chromate/no-rinse conversion coating or clear anodize is typical; decorative anodizing looks duller than 1xxx and heavy caustic etching removes the thin sacrificial layer.
Can 7072-O be formed, bent or molded?
Excellent cold formability in O temper — deep drawing, fin corrugation and roll bonding are routine; H1x tempers trade ductility for fin stiffness.
What is the maximum service temperature of 7072-O?
7072-O is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 7072-O?
Yes — 7072-O is available for sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- ASTM B209 / B209M — Aluminum and Aluminum-Alloy Sheet and Plate (Alclad products) — ASTM International (2021)
- EN 573-3 Aluminium and aluminium alloys — chemical composition — CEN (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials (solution potentials of aluminium alloys) — ASM International (2005)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.