Aluminum 7108-T651
Temper
AA 7108
T651 = t6, stress relieved by stretching
Choose when machined parts must stay dimensionally stable after heavy stock removal.
Values for the T651 condition
Other 7108 tempers and conditions
7108 is listed in 10 conditions; see the grade overview at 7108.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition for severe forming or straightening before re-heat-treatment. | 75 | 155 | 20 | 45 HB | 39 % IACS |
As fabricated | Mill state of press-exit material sold for further heat treatment or as non-structural sections. | 150 | 250 | 16 | 70 HB | 34 % IACS |
Solution heat treated and naturally aged | Use when sections must be bent, roll-formed or stretch-bent before final artificial aging. | 175 | 280 | 18 | 80 HB | 30 % IACS |
As-welded deposit | Design basis for welded joints in T6 profiles; strength largely recovers after several weeks of natural aging. | 205 | 290 | 10 | 85 HB | 32 % IACS |
Cooled from hot working and artificially aged | Cheapest strengthened condition for press-quenchable profiles where T6 dimensional accuracy is not required. | 295 | 335 | 11 | 100 HB | 33 % IACS |
Solution heat treated and overaged (stabilized) | Pick for thick welded sections or corrosive/humid service where SCC risk outweighs 10 % strength loss. | 295 | 335 | 13 | 100 HB | 37 % IACS |
Overaged for exfoliation-corrosion resistance | Intermediate overage: better exfoliation/SCC resistance than T6 with most of its strength. | 315 | 350 | 12 | 105 HB | 35 % IACS |
T6Default Solution heat treated and artificially aged | Default stocked condition: maximum strength for welded structural profiles and crash members. | 340 | 370 | 11 | 110 HB | 33 % IACS |
T651This page T6, stress relieved by stretching | Choose when machined parts must stay dimensionally stable after heavy stock removal. | 345 | 375 | 10 | 112 HB | 33 % IACS |
Very slightly overaged | Automotive bumper-beam/crash-box temper: near-T6 strength with improved bendability and crash folding behaviour. | 355 | 385 | 12 | 112 HB | 34 % IACS |
What is 7108-T651?
7108-T651 is 7108 in the T651 temper — choose when machined parts must stay dimensionally stable after heavy stock removal. 7108-T651 has a yield strength of 345 MPa (50 ksi) and a tensile strength of 375 MPa (54.4 ksi) — stronger than 83% of aluminum grades. Elongation at break is 10% and the elastic modulus is 70 GPa (10.2 Msi). 7108-T651 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). T6 is the default condition FabDigit quotes; T651 is available on request or by drawing note.
Advantages
- High strength — 345 MPa (50 ksi), better than 83% of aluminum grades
- Conducts heat well — 160 W/m·K (92.4 BTU/hr·ft·°F), better than 76% of aluminum grades
Limitations
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
7108-T651 properties
Typical room-temperature values for 7108-T651; 22 are specific to this condition. Other listed values are 7108 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
7108-T651 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).
Mechanical12
7108-T651 has a yield strength of 345 MPa (50 ksi) and a tensile strength of 375 MPa (54.4 ksi) — stronger than 83% of aluminum grades. Elongation at break is 10% and the elastic modulus is 70 GPa (10.2 Msi).
Thermal6
7108-T651 is rated for continuous service to 120°C (248 °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
7108-T651 conducts electricity at 33 % IACS, worse than 57% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (50/100), worse than 56% of aluminum grades.
Sustainability4
Producing a kilogram of 7108-T651 takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 25%.
Manufacturability8
7108-T651's machinability is good (62/100, better than 55% of aluminum grades); weldability very good (80/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 7108-T651
Is 7108 easy to machine?
Machines well in T5/T6 with sharp polished-flute carbide tools, high speed and generous coolant; O/T4 tempers are gummy and give poor surface finish.
Can 7108 be welded?
Excellent MIG/TIG and FSW behaviour with 5356/5183 filler; HAZ softening is partly recovered by natural aging, but keep the HAZ out of sustained tensile short-transverse stress to avoid SCC.
Can 7108 be formed, bent or molded?
Best formed in T4/T5 (stretch-bending, roll-forming) with generous bend radii; T6/T79 tolerate only mild bends and press-quenching from the extrusion press is standard for thin profiles.
What surface finishes work on 7108?
Takes clear and hard anodizing well (slightly grey/yellow tint versus 6060/6063), chromate-free conversion coating and powder paint are common for automotive profiles.
7108 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 | ≤ 0.1 | 0.06 |
| Femax (7108A allows up to 0.15) | ≤ 0.1 | 0.07 |
| Cumax; Cu-free class for weldability | ≤ 0.05 | 0.02 |
| Mn | ≤ 0.05 | 0.02 |
| Mg | 0.7 – 1.4 | 1 |
| Cr | ≤ 0.05 | 0.02 |
| Zn | 4.5 – 5.5 | 5 |
| Zrrecrystallisation control | 0.12 – 0.25 | 0.16 |
| Ti | ≤ 0.05 | 0.02 |
| Others (each)each | ≤ 0.05 | — |
| Others (total)total | ≤ 0.15 | — |
| Al | balance | — |
7108-T651 — frequently asked
What is 7108-T651 used for?
7108-T651 is typically used for welded structural extrusions, transport frames and ladders. In short: weldable 7000-series extrusion alloy; HAZ recovers by natural aging; stronger than 6082.
What is the yield strength of 7108-T651?
7108-T651 has a typical yield strength of 345 MPa (50 ksi) and a tensile strength of 375 MPa (54.4 ksi) — stronger than 83% of aluminum grades. Strength varies by condition: see the 10 listed tempers.
Is 7108-T651 easy to machine?
Reasonably — machinability is rated good (62/100, better than 55% of aluminum grades). Machines well in T5/T6 with sharp polished-flute carbide tools, high speed and generous coolant; O/T4 tempers are gummy and give poor surface finish.
Can 7108-T651 be welded?
Yes — weldability is rated very good (80/100). Excellent MIG/TIG and FSW behaviour with 5356/5183 filler; HAZ softening is partly recovered by natural aging, but keep the HAZ out of sustained tensile short-transverse stress to avoid SCC.
What surface finishes work on 7108-T651?
Takes clear and hard anodizing well (slightly grey/yellow tint versus 6060/6063), chromate-free conversion coating and powder paint are common for automotive profiles.
Can 7108-T651 be formed, bent or molded?
Best formed in T4/T5 (stretch-bending, roll-forming) with generous bend radii; T6/T79 tolerate only mild bends and press-quenching from the extrusion press is standard for thin profiles.
What is the maximum service temperature of 7108-T651?
7108-T651 is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 7108-T6 and 7108-O?
T6 is the default condition — default stocked condition: maximum strength for welded structural profiles and crash members. O: softest condition for severe forming or straightening before re-heat-treatment. Yield strength is 340 MPa in T6 versus 75 MPa in O.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- ASM Handbook Vol. 2: Properties and Selection — Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Handbook Vol. 13B: Corrosion — Materials (Al-Zn-Mg corrosion & SCC) — ASM International (2005)
- Extrusion alloy data for Al-Zn-Mg automotive profiles (7003/7108 class) — Hydro Aluminium Extrusion (2021)
- EN 755-2 Aluminium and aluminium alloys — Extruded rod/bar, tube and profiles: mechanical properties — CEN (2016)
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.