Aluminum 6181 · temper
Aluminum 6181-T4
Properties of the T4 condition, compared with the other 6181 tempers.
Standard automotive body-sheet delivery condition: formable now, strengthened later by paint-bake.
What is 6181-T4?
6181-T4 is 6181 in the T4 temper — standard automotive body-sheet delivery condition: formable now, strengthened later by paint-bake. 6181-T4 has a yield strength of 130 MPa (18.9 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 74% of aluminum grades. Elongation at break is 25% and the elastic modulus is 69 GPa (10 Msi). 6181-T4 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 60% of aluminum grades. It melts at 585°C (1,085 °F).
Advantages
- Ductile — tolerates forming and impact — 25%, better than 94% of aluminum grades
- Forms and bends easily — 80/100, better than 89% of aluminum grades
- High electrical conductivity — 44 % IACS, better than 85% of aluminum grades
- Conducts heat well — 165 W/m·K (95.3 BTU/hr·ft·°F), better than 79% of aluminum grades
Limitations
- Limited service temperature — 100°C (212 °F), worse than 91% of aluminum grades
6181-T4 properties
Typical room-temperature values for 6181-T4 — 11 properties are specific to this condition; the rest are grade-level values shared by every 6181 temper. Each bar shows where the value sits among the aluminum grades in FabDigit's library — further right is higher.
Physical3
6181-T4 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 60% of aluminum grades. It melts at 585°C (1,085 °F).
Mechanical11
6181-T4 has a yield strength of 130 MPa (18.9 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 74% of aluminum grades. Elongation at break is 25% and the elastic modulus is 69 GPa (10 Msi).
Thermal6
6181-T4 is rated for continuous service to 100°C (212 °F). It conducts heat at 165 W/m·K (95.3 BTU/hr·ft·°F), better than 79% of aluminum grades. Thermal expansion is 23.4 µm/m·K (13 µin/in·°F).
Electrical3
6181-T4 conducts electricity at 44 % IACS, better than 85% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), better than 67% of aluminum grades.
Sustainability4
Producing a kilogram of 6181-T4 takes about 200 MJ of energy and emits 12 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 30%.
Manufacturability6
6181-T4's machinability is good (55/100, worse than 58% of aluminum grades); weldability very good (75/100); formability very good (80/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 6181 tempers and conditions
6181 is also supplied in 7 other conditions. The full side-by-side table is on the 6181 overview.
- T6Use where full strength and dent resistance are needed and no further deep forming is required.275 MPa yield · 95 HB
- T4Standard automotive body-sheet delivery condition: formable now, strengthened later by paint-bake.130 MPa yield · 70 HB
- OChoose for maximum drawability or when the part is heat treated after forming.60 MPa yield · 33 HB
Working with 6181-T4
Is 6181 easy to machine?
Machines easily with sharp polished-flute carbide tools and high speeds; T4 tends to smear so prefer T6/aged material or flood lubrication for fine finishes.
Can 6181 be welded?
Readily resistance-spot, laser and MIG/TIG welded with 4043 (crack resistance) or 5356 (strength/anodizing); HAZ softening means post-weld aging or joint design allowance is needed.
Can 6181 be formed, bent or molded?
Excellent stretch/deep-draw behaviour in T4 or T4P (good r-value and n-value for outer panels); avoid forming in T6 and control natural-aging time to preserve bendability.
What surface finishes work on 6181?
Takes conversion coating, e-coat and paint very well (its normal automotive route); protective anodizing is good, decorative bright anodizing gives a grey cast due to high Si.
6181 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 | 0.8 – 1.2 | 1 |
| Feimpurity limit | ≤ 0.45 | 0.25 |
| Cu | ≤ 0.1 | 0.05 |
| Mn | ≤ 0.15 | 0.07 |
| Mg | 0.6 – 1 | 0.8 |
| Cr | ≤ 0.1 | 0.02 |
| Zn | ≤ 0.2 | 0.05 |
| Ti | ≤ 0.1 | 0.02 |
| Others (each)others total 0.15 max | ≤ 0.05 | — |
| Al | balance | — |
6181-T4 — frequently asked
What is 6181-T4 used for?
6181-T4 is typically used for automotive outer body sheet panels, door inner panels, hood and roof outer skins, hemmed closure panels, fenders and quarter panels and tailgate and deck-lid panels. In short: auto body sheet alloy.
What is the yield strength of 6181-T4?
6181-T4 has a typical yield strength of 130 MPa (18.9 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 74% of aluminum grades. Strength varies by condition: see the 8 listed tempers.
Is 6181-T4 easy to machine?
Reasonably — machinability is rated good (55/100, worse than 58% of aluminum grades). Machines easily with sharp polished-flute carbide tools and high speeds; T4 tends to smear so prefer T6/aged material or flood lubrication for fine finishes.
Can 6181-T4 be welded?
Yes — weldability is rated very good (75/100). Readily resistance-spot, laser and MIG/TIG welded with 4043 (crack resistance) or 5356 (strength/anodizing); HAZ softening means post-weld aging or joint design allowance is needed.
What surface finishes work on 6181-T4?
Takes conversion coating, e-coat and paint very well (its normal automotive route); protective anodizing is good, decorative bright anodizing gives a grey cast due to high Si.
Can 6181-T4 be formed, bent or molded?
Excellent stretch/deep-draw behaviour in T4 or T4P (good r-value and n-value for outer panels); avoid forming in T6 and control natural-aging time to preserve bendability.
What is the maximum service temperature of 6181-T4?
6181-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 6181-T4?
Yes — 6181-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 (Teal Sheets) — The Aluminum Association (2018)
- EN 573-3 / EN 485-2 — Aluminium and aluminium alloys: chemical composition and mechanical properties of sheet, strip and plate — CEN (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B / Vol. 19 — Corrosion and Fatigue of Aluminum Alloys — ASM International (2005)
- Automotive body sheet AlMgSi (6xxx) product information — Constellium / Novelis / Hydro (2022)
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.