Aluminum 6070 · temper
Aluminum 6070-T4
Properties of the T4 condition, compared with the other 6070 tempers.
Choose when parts must be bent, drawn or formed after heat treatment and later aged to T6.
What is 6070-T4?
6070-T4 is 6070 in the T4 temper — choose when parts must be bent, drawn or formed after heat treatment and later aged to T6. 6070-T4 has a yield strength of 172 MPa (24.9 ksi) and a tensile strength of 315 MPa (45.7 ksi) — weaker than 56% of aluminum grades. Elongation at break is 20% and the elastic modulus is 69 GPa (10 Msi). 6070-T4 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
- Ductile — tolerates forming and impact — 20%, better than 89% of aluminum grades
- Forms and bends easily — 60/100, better than 77% of aluminum grades
Limitations
- Limited service temperature — 100°C (212 °F), worse than 91% of aluminum grades
6070-T4 properties
Typical room-temperature values for 6070-T4 — 12 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-T4 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-T4 has a yield strength of 172 MPa (24.9 ksi) and a tensile strength of 315 MPa (45.7 ksi) — weaker than 56% of aluminum grades. Elongation at break is 20% and the elastic modulus is 69 GPa (10 Msi).
Thermal6
6070-T4 is rated for continuous service to 100°C (212 °F). It conducts heat at 154 W/m·K (89 BTU/hr·ft·°F), better than 68% of aluminum grades. Thermal expansion is 23.5 µm/m·K (13.1 µin/in·°F).
Electrical3
6070-T4 conducts electricity at 39 % IACS, better than 65% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), better than 57% of aluminum grades.
Sustainability4
Producing a kilogram of 6070-T4 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-T4's machinability is fair (50/100, worse than 65% of aluminum grades); weldability very good (70/100); formability good (60/100).
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-T4
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-T4 — frequently asked
What is 6070-T4 used for?
6070-T4 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-T4?
6070-T4 has a typical yield strength of 172 MPa (24.9 ksi) and a tensile strength of 315 MPa (45.7 ksi) — weaker than 56% of aluminum grades. Strength varies by condition: see the 6 listed tempers.
Is 6070-T4 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 65% 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-T4 be welded?
Yes — weldability is rated very good (70/100). 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-T4?
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-T4 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-T4?
6070-T4 is rated for continuous use to about 100°C (212 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 6070-T4?
Yes — 6070-T4 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.