Aluminum 1070A-O (Annealed)
Temper · default condition
AA 1070A · EN AW-1070A, 3.0275
Pick for maximum ductility, deep drawing, spinning and best bright-anodizing appearance.
Values for the O condition
Other 1070A tempers and conditions
1070A is listed in 11 conditions; see the grade overview at 1070A.
Compare all 11 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefaultThis page Annealed | Pick for maximum ductility, deep drawing, spinning and best bright-anodizing appearance. | 25 | 70 | 40 | 20 HB | 61.5 % IACS |
Slightly strain hardened | Pick for sheet/plate that received minor straightening or flattening after annealing but must stay essentially soft. | 28 | 72 | 33 | 21 HB | 61.5 % IACS |
As fabricated | Pick for hot-rolled plate, extrusions or forgings where properties are not guaranteed and further working/annealing follows. | 30 | 75 | 32 | 21 HB | 61 % IACS |
Strain hardened from hot working only | Pick for thicker hot-rolled plate or extrusions where a guaranteed minimum strength is required without cold work. | 35 | 75 | 25 | 23 HB | 61 % IACS |
Strain hardened and partially annealed, quarter hard | Pick when H12-level strength is wanted with better ductility and flatness stability from a stabilizing partial anneal. | 58 | 85 | 15 | 24 HB | 61 % IACS |
Strain hardened, quarter hard | Pick when a modest strength gain over O is needed while keeping good bendability. | 70 | 90 | 12 | 25 HB | 61 % IACS |
Strain hardened and partially annealed, half hard | Pick for half-hard strip that must still bend or roll-form without cracking — common for trim and reflectors. | 74 | 100 | 11 | 28 HB | 60.5 % IACS |
Strain hardened, half hard | Pick as the general-purpose stiffer sheet temper for panels, nameplates and cladding with mild forming. | 88 | 105 | 8 | 30 HB | 60.5 % IACS |
Strain hardened and partially annealed, three-quarter hard | Pick for stiff strip needing more residual ductility and shape stability than H16. | 90 | 115 | 7 | 32 HB | 60 % IACS |
Strain hardened, three-quarter hard | Pick for stiffer flat strip or shallow-formed parts where springiness and dent resistance matter. | 102 | 120 | 5 | 34 HB | 60 % IACS |
Strain hardened, full hard | Pick for thin foil/strip, reflector sheet and applications needing the highest strength and smoothest as-rolled surface. | 115 | 135 | 4 | 38 HB | 59.5 % IACS |
What is 1070A-O?
1070A-O is 1070A in the O temper — pick for maximum ductility, deep drawing, spinning and best bright-anodizing appearance. 1070A-O has a yield strength of 25 MPa (3.63 ksi) and a tensile strength of 70 MPa (10.2 ksi) — weaker than 98% of aluminum grades. Elongation at break is 40% and the elastic modulus is 69 GPa (10 Msi). 1070A-O has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 646°C (1,195 °F).
Advantages
- Readily welded — 95/100, better than 99% of aluminum grades
- Ductile — tolerates forming and impact — 40%, better than 98% of aluminum grades
- Forms and bends easily — 98/100, better than 98% of aluminum grades
- Polishes to a fine finish — 90/100, better than 98% of aluminum grades
- Conducts heat well — 231 W/m·K (133.5 BTU/hr·ft·°F), better than 97% of aluminum grades
Limitations
- Low strength — 25 MPa (3.63 ksi), worse than 98% of aluminum grades
- Difficult to machine — 30/100, worse than 92% of aluminum grades
1070A-O properties
Typical room-temperature values for 1070A-O; 14 are specific to this condition. Other listed values are 1070A reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
1070A-O has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 646°C (1,195 °F).
Mechanical11
1070A-O has a yield strength of 25 MPa (3.63 ksi) and a tensile strength of 70 MPa (10.2 ksi) — weaker than 98% of aluminum grades. Elongation at break is 40% and the elastic modulus is 69 GPa (10 Msi).
Thermal6
1070A-O is rated for continuous service to 150°C (302 °F). It conducts heat at 231 W/m·K (133.5 BTU/hr·ft·°F), better than 97% of aluminum grades. Thermal expansion is 23.6 µm/m·K (13.1 µin/in·°F).
Electrical3
1070A-O conducts electricity at 61.5 % IACS, better than 97% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is very good (76/100), better than 90% of aluminum grades.
Sustainability4
Producing a kilogram of 1070A-O takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 76% of aluminum grades. Typical recycled content is 5%.
Manufacturability7
1070A-O's machinability is poor (30/100, worse than 92% of aluminum grades); weldability excellent (95/100); formability excellent (98/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1070A-O
Is 1070A easy to machine?
Very gummy — use polished high-rake carbide, high speed, sharp tools and flood coolant/lubricant to avoid built-up edge and tearing.
Can 1070A be welded?
Excellent with TIG/MIG using 1100 or 1188 pure-Al filler; joints are soft and any cold work is lost in the HAZ.
Can 1070A be formed, bent or molded?
Outstanding cold formability in O/H1x2 tempers — deep drawing, spinning, embossing and foil rolling; interanneal around 340–400 °C after heavy work.
What surface finishes work on 1070A?
Ideal for bright-dip, clear and specular anodizing and chemical/electro-brightening; the low Fe/Si keeps films colourless, and it also takes electroless plating and paint after conversion coating.
1070A 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 |
|---|---|---|
| SiEN 573-3 limit | ≤ 0.2 | 0.08 |
| Fetighter than 1070 practice | ≤ 0.25 | 0.15 |
| Cu | ≤ 0.03 | 0.01 |
| Mn | ≤ 0.03 | 0.01 |
| Mg | ≤ 0.03 | 0.01 |
| Zn | ≤ 0.07 | 0.02 |
| Ti | ≤ 0.03 | 0.01 |
| Others (each)each other element | ≤ 0.03 | — |
| Alminimum aluminium content | ≥ 99.7 (balance) | — |
1070A-O — frequently asked
What is 1070A-O used for?
1070A-O is typically used for anodized architectural trim, reflectors, chemical tanks and electrical parts. In short: low Fe/Si for clear anodizing; near-maximum formability; softest practical sheet grade.
What is the yield strength of 1070A-O?
1070A-O has a typical yield strength of 25 MPa (3.63 ksi) and a tensile strength of 70 MPa (10.2 ksi) — weaker than 98% of aluminum grades. Strength varies by condition: see the 11 listed tempers.
Is 1070A-O easy to machine?
Not especially — machinability is rated poor (30/100, worse than 92% of aluminum grades). Very gummy — use polished high-rake carbide, high speed, sharp tools and flood coolant/lubricant to avoid built-up edge and tearing.
Can 1070A-O be welded?
Yes — weldability is rated excellent (95/100). Excellent with TIG/MIG using 1100 or 1188 pure-Al filler; joints are soft and any cold work is lost in the HAZ.
What surface finishes work on 1070A-O?
Ideal for bright-dip, clear and specular anodizing and chemical/electro-brightening; the low Fe/Si keeps films colourless, and it also takes electroless plating and paint after conversion coating.
Can 1070A-O be formed, bent or molded?
Outstanding cold formability in O/H1x2 tempers — deep drawing, spinning, embossing and foil rolling; interanneal around 340–400 °C after heavy work.
What is the maximum service temperature of 1070A-O?
1070A-O is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1070A-O and 1070A-H18?
O is the default condition — pick for maximum ductility, deep drawing, spinning and best bright-anodizing appearance. H18: pick for thin foil/strip, reflector sheet and applications needing the highest strength and smoothest as-rolled surface. Yield strength is 25 MPa in O versus 115 MPa in H18.
Sources
- EN 573-3 Aluminium and aluminium alloys — chemical composition — CEN (2019)
- EN 485-2 Aluminium sheet, strip and plate — mechanical properties — CEN (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- International Alloy Designations and Chemical Composition Limits (Teal Sheets) — The Aluminum Association (2018)
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.