Aluminum 7N01-O (Annealed)
Temper
GB 7N01 · JIS A7N01
Softest condition for severe forming or deep bending before re-solution treating and ageing.
Values for the O condition
Other 7N01 tempers and conditions
7N01 is listed in 9 conditions; see the grade overview at 7N01.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
OThis page Annealed | Softest condition for severe forming or deep bending before re-solution treating and ageing. | 120 | 225 | 20 | 65 HB | 40 % IACS |
As fabricated | Mill stock for customers who will heat treat or age the parts themselves; properties are not guaranteed. | 200 | 300 | 15 | 80 HB | 33 % IACS |
Solution heat treated and naturally aged | Choose when parts must be formed or welded first and allowed to re-age naturally to useful strength. | 210 | 330 | 17 | 90 HB | 32 % IACS |
T5Default Cooled from hot working and artificially aged | Default rolling-stock extrusion condition: good strength/weldability balance with press-quench economics. | 285 | 355 | 13 | 105 HB | 35 % IACS |
Solution heat treated and overaged for stress-corrosion resistance | Use where SCC and exfoliation resistance outweigh a 10–15 % strength penalty versus T6. | 290 | 345 | 13 | 105 HB | 38 % IACS |
Overaged between T73 and T76 | Compromise temper: most of T6 strength with much of the T73 stress-corrosion benefit. | 300 | 360 | 12 | 110 HB | 37 % IACS |
Overaged for exfoliation-corrosion resistance | Select for thin sections and skins exposed to marine or de-icing environments where exfoliation is the risk. | 310 | 365 | 12 | 112 HB | 36 % IACS |
Solution heat treated and artificially aged | Pick for maximum strength in welded frames and plate parts where full solution treatment is possible. | 320 | 375 | 12 | 115 HB | 34 % IACS |
T6, stress relieved by stretching | Plate temper for machined parts where low residual stress and dimensional stability matter. | 330 | 380 | 11 | 118 HB | 34 % IACS |
What is 7N01-O?
7N01-O is 7N01 in the O temper — softest condition for severe forming or deep bending before re-solution treating and ageing. 7N01-O has a yield strength of 120 MPa (17.4 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 77% of aluminum grades. Elongation at break is 20% and the elastic modulus is 70 GPa (10.2 Msi). 7N01-O has a density of 2.78 g/cm³ (0.1 lb/in³), heavier than 74% of aluminum grades. It melts at 600°C (1,112 °F). T5 is the default condition FabDigit quotes; O is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 48 MPa·√m (43.7 ksi·√in), better than 100% of aluminum grades
- Readily welded — 90/100, better than 90% of aluminum grades
- Ductile — tolerates forming and impact — 20%, better than 89% of aluminum grades
- Forms and bends easily — 80/100, better than 89% of aluminum grades
- Conducts heat well — 160 W/m·K (92.4 BTU/hr·ft·°F), better than 76% of aluminum grades
Limitations
- Low strength — 120 MPa (17.4 ksi), worse than 77% of aluminum grades
7N01-O properties
Typical room-temperature values for 7N01-O; 21 are specific to this condition. Other listed values are 7N01 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
7N01-O has a density of 2.78 g/cm³ (0.1 lb/in³), heavier than 74% of aluminum grades. It melts at 600°C (1,112 °F).
Mechanical13
7N01-O has a yield strength of 120 MPa (17.4 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 77% of aluminum grades. Elongation at break is 20% and the elastic modulus is 70 GPa (10.2 Msi).
Thermal6
7N01-O is rated for continuous service to 150°C (302 °F). It conducts heat at 160 W/m·K (92.4 BTU/hr·ft·°F), better than 76% of aluminum grades. Thermal expansion is 23.4 µm/m·K (13 µin/in·°F).
Electrical3
7N01-O conducts electricity at 40 % IACS, better than 72% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 51% of aluminum grades.
Sustainability4
Producing a kilogram of 7N01-O takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 76% of aluminum grades. Typical recycled content is 25%.
Manufacturability8
7N01-O's machinability is fair (45/100, worse than 72% of aluminum grades); weldability excellent (90/100); formability very good (80/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 7N01-O
Is 7N01 easy to machine?
Machines well in aged tempers with sharp carbide tools, high speed and generous coolant; softer T4/O tempers tend to smear and give stringy chips.
Can 7N01 be welded?
Excellent MIG/TIG weldability with ER5356 or Al-Zn-Mg filler; HAZ softens on welding but recovers most strength by natural re-ageing over weeks, so keep welded joints out of long-term wet chloride exposure unless post-weld aged.
Can 7N01 be formed, bent or molded?
Form in O or T4 and age afterwards; aged T5/T6 material has limited bend ductility and needs generous bend radii (≥3–4 t).
What surface finishes work on 7N01?
Takes clear and hard anodizing well and paints readily after chromate-free pretreatment; dyed decorative anodizing can look grey-cast compared with 6000-series alloys.
7N01 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 |
|---|---|---|
| Si | ≤ 0.3 | 0.15 |
| Fe | ≤ 0.35 | 0.2 |
| Cukept low for weldability and SCC resistance | ≤ 0.2 | 0.05 |
| Mn | 0.2 – 0.7 | 0.35 |
| Mg | 1 – 2 | 1.4 |
| Cr | ≤ 0.3 | 0.1 |
| Zn | 4 – 5 | 4.5 |
| Ti | ≤ 0.2 | 0.03 |
| ZrZr+Ti total limited to 0.25 % | ≤ 0.25 | 0.15 |
| V | ≤ 0.1 | — |
| Others (each)total 0.15 % max | ≤ 0.05 | — |
| Al | balance | — |
7N01-O — frequently asked
What is 7N01-O used for?
7N01-O is typically used for railway car bodies, welded structural extrusions and vehicle frames. In short: weldable high-strength 7000 series; rolling-stock body alloy; HAZ re-ages naturally.
What is the yield strength of 7N01-O?
7N01-O has a typical yield strength of 120 MPa (17.4 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 77% of aluminum grades. Strength varies by condition: see the 9 listed tempers.
Is 7N01-O easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 72% of aluminum grades). Machines well in aged tempers with sharp carbide tools, high speed and generous coolant; softer T4/O tempers tend to smear and give stringy chips.
Can 7N01-O be welded?
Yes — weldability is rated excellent (90/100). Excellent MIG/TIG weldability with ER5356 or Al-Zn-Mg filler; HAZ softens on welding but recovers most strength by natural re-ageing over weeks, so keep welded joints out of long-term wet chloride exposure unless post-weld aged.
What surface finishes work on 7N01-O?
Takes clear and hard anodizing well and paints readily after chromate-free pretreatment; dyed decorative anodizing can look grey-cast compared with 6000-series alloys.
Can 7N01-O be formed, bent or molded?
Form in O or T4 and age afterwards; aged T5/T6 material has limited bend ductility and needs generous bend radii (≥3–4 t).
What is the maximum service temperature of 7N01-O?
7N01-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 7N01-T5 and 7N01-O?
T5 is the default condition — default rolling-stock extrusion condition: good strength/weldability balance with press-quench economics. O: softest condition for severe forming or deep bending before re-solution treating and ageing. Yield strength is 285 MPa in T5 versus 120 MPa in O.
Sources
- JIS H 4100 — Aluminium and aluminium alloy extruded shapes — Japanese Standards Association (2015)
- JIS H 4000 — Aluminium and aluminium alloy sheets, strips and plates — Japanese Standards Association (2014)
- JIS E 4001 / rolling stock structural material practice — Japanese Standards Association (2011)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials (Al-Zn-Mg SCC behaviour) — ASM International (2005)
- International Alloy Designations and Chemical Composition Limits (Teal Sheets) — 7020/7005 comparison — The Aluminum Association (2018)
- SMM / Mysteel aluminium extrusion price references — SMM (2026)
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.