Aluminum 7178-T62
Temper
AA 7178 · UNS A97178 · EN AW-7178, AW 7178
T62 = t6, heat treated by the user
7178 re-solution-treated from O/F temper and artificially aged by the fabricator; strength essentially equals T6 with no stretch stress relief.
Values for the T62 condition
Other 7178 tempers and conditions
7178 is listed in 8 conditions; see the grade overview at 7178.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Soft annealed stock for severe forming or machining before solution heat treatment and aging. | 103 | 228 | 15 | 60 HB | 38 % IACS |
Overaged for exfoliation-corrosion resistance | Choose when exfoliation-corrosion resistance matters more than the last 5 % of strength. | 505 | 570 | 11 | 150 HB | 38 % IACS |
T76, stress relieved by stretching | Over-aged plate with low residual stress — for machined skins needing exfoliation resistance and dimensional stability. | 510 | 572 | 10 | 150 HB | 38 % IACS |
T62This page T6, heat treated by the user | 7178 re-solution-treated from O/F temper and artificially aged by the fabricator; strength essentially equals T6 with no stretch stress relief. | 530 | 600 | 10 | 160 HB | 31 % IACS |
T6, stress relieved by stretching | Standard plate temper — same peak strength as T6 but low residual stress for stable machining of thick parts. | 530 | 600 | 9 | 160 HB | 31 % IACS |
Solution heat treated and artificially aged | Peak-strength condition — pick it for maximum static and compressive strength in sheet, clad sheet and simple sections. | 538 | 607 | 10 | 160 HB | 31 % IACS |
Solution treated, stretched, aged; extrusion without straightening… | Extruded stringer/section temper with controlled stretch and no subsequent straightening. | 570 | 620 | 8 | 165 HB | 31 % IACS |
T6, stress relieved by stretching, minor straightening | Most common high-strength extrusion temper — straightness-corrected version of T6510. | 570 | 620 | 8 | 165 HB | 31 % IACS |
What is 7178-T62?
7178-T62 is 7178 in the T62 temper — 7178 re-solution-treated from O/F temper and artificially aged by the fabricator; strength essentially equals T6 with no stretch stress relief. 7178-T62 has a yield strength of 530 MPa (76.9 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 97% of aluminum grades. Elongation at break is 10% and the elastic modulus is 71.7 GPa (10.4 Msi). 7178-T62 has a density of 2.83 g/cm³ (0.102 lb/in³), heavier than 91% of aluminum grades. It melts at 477°C (891 °F).
Advantages
- High strength — 530 MPa (76.9 ksi), better than 97% of aluminum grades
Limitations
- Difficult to weld — 15/100, worse than 96% of aluminum grades
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
- Needs corrosion protection — 38/100, worse than 79% of aluminum grades
7178-T62 properties
Typical room-temperature values for 7178-T62; 34 are specific to this condition. Other listed values are 7178 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
7178-T62 has a density of 2.83 g/cm³ (0.102 lb/in³), heavier than 91% of aluminum grades. It melts at 477°C (891 °F).
Mechanical13
7178-T62 has a yield strength of 530 MPa (76.9 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 97% of aluminum grades. Elongation at break is 10% and the elastic modulus is 71.7 GPa (10.4 Msi).
Thermal6
7178-T62 is rated for continuous service to 120°C (248 °F). It conducts heat at 125 W/m·K (72.2 BTU/hr·ft·°F), worse than 72% of aluminum grades. Thermal expansion is 23.4 µm/m·K (13 µin/in·°F).
Electrical3
7178-T62 conducts electricity at 31 % IACS, worse than 68% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (38/100), worse than 79% of aluminum grades.
Sustainability4
Producing a kilogram of 7178-T62 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 25%.
Manufacturability7
7178-T62's machinability is very good (70/100, better than 72% of aluminum grades); weldability poor (15/100); formability poor (22/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 7178-T62
Is 7178 easy to machine?
Machines well in T6/T76 with sharp carbide, high speed and flood coolant; relieve stresses (T651/T7651) before heavy pocket milling to control distortion.
Can 7178 be welded?
Not fusion weldable — hot cracking and severe HAZ SCC; join by riveting, bolting or adhesive bonding (friction-stir only with qualified procedures).
Can 7178 be formed, bent or molded?
Form in O or freshly quenched W temper and age afterwards; T6 sheet tolerates only large-radius bends and is prone to cracking.
What surface finishes work on 7178?
Clad or anodize (chromic/sulfuric) plus chromate conversion and primer for corrosion protection; avoid sustained short-transverse tensile stress and use T76 tempers in exfoliation-prone areas.
7178 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 | ≤ 0.4 | |
| Fe | ≤ 0.5 | |
| Cu | 1.6 – 2.4 | 2 |
| Mn | ≤ 0.3 | |
| Mg | 2.4 – 3.1 | 2.7 |
| Cr | 0.18 – 0.28 | 0.23 |
| Zn | 6.3 – 7.3 | 6.8 |
| Ti | ≤ 0.2 | |
| Others (each)each | ≤ 0.05 | |
| Others (total)total | ≤ 0.15 | |
| Al | balance |
7178-T62 — frequently asked
What is 7178-T62 used for?
7178-T62 is typically used for aircraft upper wing skins, wing stringers, compression-loaded airframe panels, extruded stiffeners and spar caps, alclad aerospace sheet components and legacy airframe replacement parts. In short: compression aerospace alloy.
What is the yield strength of 7178-T62?
7178-T62 has a typical yield strength of 530 MPa (76.9 ksi) and a tensile strength of 600 MPa (87 ksi) — stronger than 97% of aluminum grades. Strength varies by condition: see the 8 listed tempers.
Is 7178-T62 easy to machine?
Yes — machinability is rated very good (70/100, better than 72% of aluminum grades). Machines well in T6/T76 with sharp carbide, high speed and flood coolant; relieve stresses (T651/T7651) before heavy pocket milling to control distortion.
Can 7178-T62 be welded?
Not readily — weldability is rated poor (15/100). Not fusion weldable — hot cracking and severe HAZ SCC; join by riveting, bolting or adhesive bonding (friction-stir only with qualified procedures).
What surface finishes work on 7178-T62?
Clad or anodize (chromic/sulfuric) plus chromate conversion and primer for corrosion protection; avoid sustained short-transverse tensile stress and use T76 tempers in exfoliation-prone areas.
Can 7178-T62 be formed, bent or molded?
Form in O or freshly quenched W temper and age afterwards; T6 sheet tolerates only large-radius bends and is prone to cracking.
What is the maximum service temperature of 7178-T62?
7178-T62 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.
Can FabDigit make parts in 7178-T62?
Yes — 7178-T62 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
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 — ASM International (1990)
- MMPDS-17 Metallic Materials Properties Development and Standardization — Battelle/FAA (2022)
- ASTM B209 / B221 — Aluminum Sheet, Plate and Extruded Products — ASTM International (2021)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
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.