Aluminum 6070 · temper
Aluminum 6070-O
Properties of the O condition, compared with the other 6070 tempers.
Pick for maximum formability before solution treating and aging.
What is 6070-O?
6070-O is 6070 in the O temper — pick for maximum formability before solution treating and aging. 6070-O has a yield strength of 69 MPa (10 ksi) and a tensile strength of 145 MPa (21 ksi) — weaker than 92% of aluminum grades. Elongation at break is 20% and the elastic modulus is 69 GPa (10 Msi). 6070-O has a density of 2.71 g/cm³ (0.0979 lb/in³), heavier than 51% of aluminum grades. It melts at 566°C (1,051 °F).
Advantages
- Conducts heat well — 201 W/m·K (116.1 BTU/hr·ft·°F), better than 92% of aluminum grades
- Forms and bends easily — 85/100, better than 91% of aluminum grades
- Ductile — tolerates forming and impact — 20%, better than 89% of aluminum grades
- High electrical conductivity — 47 % IACS, better than 88% of aluminum grades
Limitations
- Low strength — 69 MPa (10 ksi), worse than 92% of aluminum grades
- Difficult to machine — 35/100, worse than 86% of aluminum grades
6070-O properties
Typical room-temperature values for 6070-O — 11 properties are specific to this condition; the rest are grade-level values shared by every 6070 temper. Each bar shows where the value sits among the aluminum grades in FabDigit's library — further right is higher.
Physical3
6070-O has a density of 2.71 g/cm³ (0.0979 lb/in³), heavier than 51% of aluminum grades. It melts at 566°C (1,051 °F).
Mechanical12
6070-O has a yield strength of 69 MPa (10 ksi) and a tensile strength of 145 MPa (21 ksi) — weaker than 92% of aluminum grades. Elongation at break is 20% and the elastic modulus is 69 GPa (10 Msi).
Thermal6
6070-O is rated for continuous service to 150°C (302 °F). It conducts heat at 201 W/m·K (116.1 BTU/hr·ft·°F), better than 92% of aluminum grades. Thermal expansion is 23.5 µm/m·K (13.1 µin/in·°F).
Electrical3
6070-O conducts electricity at 47 % IACS, better than 88% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), better than 57% of aluminum grades.
Sustainability4
Producing a kilogram of 6070-O takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 30%.
Manufacturability7
6070-O's machinability is fair (35/100, worse than 86% of aluminum grades); weldability very good (75/100); formability excellent (85/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 6070 tempers and conditions
6070 is also supplied in 5 other conditions. The full side-by-side table is on the 6070 overview.
- T6Standard high-strength condition for structural extrusions, forgings and machined parts.350 MPa yield · 120 HB
- T62High-strength Al-Mg-Si-Cu extrusion alloy re-solutionized from O/F stock and artificially aged, giving T6-level strength with good weldability.350 MPa yield · 120 HB
- T4Choose when parts must be bent, drawn or formed after heat treatment and later aged to T6.172 MPa yield · 90 HB
- OPick for maximum formability before solution treating and aging.69 MPa yield · 35 HB
Working with 6070-O
Is 6070 easy to machine?
Machines cleanly in T6/T6511 with sharp carbide tooling, high speed and flood or mist lubrication; chips are shorter than 6061-T6.
Can 6070 be welded?
Readily GMAW/GTAW welded with 4043 (or 5356 for anodized appearance); HAZ drops toward T4 strength, so post-weld aging or joint design allowance is needed and crater cracking must be avoided.
Can 6070 be formed, bent or molded?
Form, bend and forge in O or T4; T6 material has limited bend radius. Extrusion speeds are lower and press pressures higher than for 6063/6061 because of the Si-Mn-Cu load.
What surface finishes work on 6070?
Takes hard and protective anodize well and accepts chromate/paint systems; clear decorative anodize is slightly darker/off-tint due to Cu and Mn, so match-critical parts should be color-anodized or painted.
6070 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 | 1 – 1.7 | 1.4 |
| Feimpurity limit | ≤ 0.5 | 0.25 |
| Cu | 0.15 – 0.4 | 0.28 |
| Mn | 0.4 – 1 | 0.7 |
| Mg | 0.5 – 1.2 | 0.8 |
| Cr | ≤ 0.1 | — |
| Zn | ≤ 0.25 | — |
| Ti | ≤ 0.15 | — |
| Others (each)0.15 total | ≤ 0.05 | — |
| Al | balance | — |
6070-O — frequently asked
What is 6070-O used for?
6070-O is typically used for heavy structural extrusions, truck frame rails, heavy forgings, automotive and transport structural members, bicycle and motorcycle components and welded load-bearing frames. In short: heavy section forging alloy.
What is the yield strength of 6070-O?
6070-O has a typical yield strength of 69 MPa (10 ksi) and a tensile strength of 145 MPa (21 ksi) — weaker than 92% of aluminum grades. Strength varies by condition: see the 6 listed tempers.
Is 6070-O easy to machine?
Not especially — machinability is rated fair (35/100, worse than 86% of aluminum grades). Machines cleanly in T6/T6511 with sharp carbide tooling, high speed and flood or mist lubrication; chips are shorter than 6061-T6.
Can 6070-O be welded?
Yes — weldability is rated very good (75/100). Readily GMAW/GTAW welded with 4043 (or 5356 for anodized appearance); HAZ drops toward T4 strength, so post-weld aging or joint design allowance is needed and crater cracking must be avoided.
What surface finishes work on 6070-O?
Takes hard and protective anodize well and accepts chromate/paint systems; clear decorative anodize is slightly darker/off-tint due to Cu and Mn, so match-critical parts should be color-anodized or painted.
Can 6070-O be formed, bent or molded?
Form, bend and forge in O or T4; T6 material has limited bend radius. Extrusion speeds are lower and press pressures higher than for 6063/6061 because of the Si-Mn-Cu load.
What is the maximum service temperature of 6070-O?
6070-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.
Can FabDigit make parts in 6070-O?
Yes — 6070-O is available for CNC machining and 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 and Wrought Aluminum Alloys (Teal Sheets) — The Aluminum Association (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- EN 573-3 Aluminium and aluminium alloys — Chemical composition of wrought products — CEN (2019)
- ASTM B221 Standard Specification for Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes — ASTM (2021)
- Wrought aluminium alloy property records (6070-O / T4 / T6) — MatWeb / ASM Alloy Center (2023)
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.