Aluminum 6151 · temper
Aluminum 6151-T4
Properties of the T4 condition, compared with the other 6151 tempers.
Intermediate strength with good ductility; pick when bending or straightening is needed before final artificial ageing to T6.
What is 6151-T4?
6151-T4 is 6151 in the T4 temper — intermediate strength with good ductility; pick when bending or straightening is needed before final artificial ageing to T6. 6151-T4 has a yield strength of 125 MPa (18.1 ksi) and a tensile strength of 220 MPa (31.9 ksi) — weaker than 75% of aluminum grades. Elongation at break is 22% and the elastic modulus is 69 GPa (10 Msi). 6151-T4 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 60% of aluminum grades. It melts at 588°C (1,090 °F).
Advantages
- Ductile — tolerates forming and impact — 22%, better than 91% of aluminum grades
- Conducts heat well — 165 W/m·K (95.3 BTU/hr·ft·°F), better than 79% of aluminum grades
- Forms and bends easily — 60/100, better than 77% of aluminum grades
- Tough — resists crack growth — 30 MPa·√m (27.3 ksi·√in), better than 76% of aluminum grades
Limitations
- Limited service temperature — 100°C (212 °F), worse than 91% of aluminum grades
- Low strength — 125 MPa (18.1 ksi), worse than 75% of aluminum grades
6151-T4 properties
Typical room-temperature values for 6151-T4 — 11 properties are specific to this condition; the rest are grade-level values shared by every 6151 temper. Each bar shows where the value sits among the aluminum grades in FabDigit's library — further right is higher.
Physical3
6151-T4 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 60% of aluminum grades. It melts at 588°C (1,090 °F).
Mechanical13
6151-T4 has a yield strength of 125 MPa (18.1 ksi) and a tensile strength of 220 MPa (31.9 ksi) — weaker than 75% of aluminum grades. Elongation at break is 22% and the elastic modulus is 69 GPa (10 Msi).
Thermal6
6151-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 µm/m·K (12.8 µin/in·°F).
Electrical3
6151-T4 conducts electricity at 40 % IACS, better than 72% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), better than 63% of aluminum grades.
Sustainability4
Producing a kilogram of 6151-T4 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 25%.
Manufacturability8
6151-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 6151 tempers and conditions
6151 is also supplied in 3 other conditions. The full side-by-side table is on the 6151 overview.
- T6Standard supply condition for 6151 die forgings and rolled rings; full strength with good toughness and machinability.295 MPa yield · 100 HB
- T652Hand/die forgings cold-compressed after quenching to remove residual stress — choose when heavy machining must stay dimensionally stable.295 MPa yield · 100 HB
- T4Intermediate strength with good ductility; pick when bending or straightening is needed before final artificial ageing to T6.125 MPa yield · 65 HB
- OSoftest condition, chosen for maximum formability or for machining before solution treatment.60 MPa yield · 35 HB
Working with 6151-T4
Is 6151 easy to machine?
Machines well in T6 with sharp polished-flute carbide tooling, high speeds and flood or MQL lubrication; gummy and prone to built-up edge in O/T4.
Can 6151 be welded?
Readily GTAW/GMAW welded with 4043 or 5356 filler; expect HAZ softening to near-T4 strength unless the part is re-solution treated and re-aged.
Can 6151 be formed, bent or molded?
Excellent hot forgeability (about 380–450 °C) — the main reason the alloy exists; cold form only in O or T4, never in T6.
What surface finishes work on 6151?
Takes clear and hard-coat anodizing well and accepts chromate/chrome-free conversion coatings and paint; bright decorative anodize is dull because of Si and Cr content.
6151 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 | 0.6 – 1.2 | 0.9 |
| Feimpurity limit | ≤ 1 | 0.4 |
| Cu | ≤ 0.35 | 0.1 |
| Mn | ≤ 0.2 | 0.05 |
| Mg | 0.45 – 0.8 | 0.6 |
| Crgrain-structure control | 0.15 – 0.35 | 0.25 |
| Zn | ≤ 0.25 | — |
| Ti | ≤ 0.15 | — |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Al | balance | — |
6151-T4 — frequently asked
What is 6151-T4 used for?
6151-T4 is typically used for forged wheel discs, brake pistons, rolled rings, die-forged machinery components, forged suspension and steering parts and hydraulic equipment forgings. In short: forged disc alloy.
What is the yield strength of 6151-T4?
6151-T4 has a typical yield strength of 125 MPa (18.1 ksi) and a tensile strength of 220 MPa (31.9 ksi) — weaker than 75% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is 6151-T4 easy to machine?
Reasonably — machinability is rated fair (50/100, worse than 65% of aluminum grades). Machines well in T6 with sharp polished-flute carbide tooling, high speeds and flood or MQL lubrication; gummy and prone to built-up edge in O/T4.
Can 6151-T4 be welded?
Yes — weldability is rated very good (70/100). Readily GTAW/GMAW welded with 4043 or 5356 filler; expect HAZ softening to near-T4 strength unless the part is re-solution treated and re-aged.
What surface finishes work on 6151-T4?
Takes clear and hard-coat anodizing well and accepts chromate/chrome-free conversion coatings and paint; bright decorative anodize is dull because of Si and Cr content.
Can 6151-T4 be formed, bent or molded?
Excellent hot forgeability (about 380–450 °C) — the main reason the alloy exists; cold form only in O or T4, never in T6.
What is the maximum service temperature of 6151-T4?
6151-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 6151-T4?
Yes — 6151-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)
- ASM Handbook Vol.2: Properties and Selection — Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASTM B247 — Aluminum-Alloy Die Forgings, Hand Forgings and Rolled Ring Forgings — ASTM (2020)
- Aluminum Standards and Data — The Aluminum Association (2017)
- MMPDS / metallic materials property typical values — Battelle (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.