Aluminum 344.0-T6
Temper
AA 344.0 · UNS A03440
T6 = solution heat treated and artificially aged
Highest strength and hardness condition for loaded pump/engine hardware; accept some distortion and higher cost.
Values for the T6 condition
Other 344.0 tempers and conditions
344.0 is listed in 4 conditions; see the grade overview at 344.0.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
FDefault As fabricated | Default stocked condition — as-cast parts where dimensional stability at room temperature and lowest cost matter. | 125 | 220 | 2 | 85 HB | 28 % IACS |
Cooled from hot working and artificially aged | Pick when moderate strength gain and dimensional/thermal stability are needed without the distortion risk of solution treatment. | 170 | 235 | 1.5 | 95 HB | 30 % IACS |
Solution heat treated and overaged (stabilized) | Choose for parts running hot or needing long-term dimensional stability, trading ~10 % strength for stability and toughness. | 190 | 250 | 2 | 90 HB | 32 % IACS |
T6This page Solution heat treated and artificially aged | Highest strength and hardness condition for loaded pump/engine hardware; accept some distortion and higher cost. | 210 | 285 | 1.5 | 105 HB | 27 % IACS |
What is 344.0-T6?
344.0-T6 is 344.0 in the T6 temper — highest strength and hardness condition for loaded pump/engine hardware; accept some distortion and higher cost. 344.0-T6 has a yield strength of 210 MPa (30.5 ksi) and a tensile strength of 285 MPa (41.3 ksi) — stronger than 56% of aluminum grades. Elongation at break is 1.5% and the elastic modulus is 74 GPa (10.7 Msi). 344.0-T6 has a density of 2.75 g/cm³ (0.0994 lb/in³), heavier than 67% of aluminum grades. It melts at 521°C (970 °F). F is the default condition FabDigit quotes; T6 is available on request or by drawing note.
Advantages
- Low embodied carbon — 9.5 kg CO₂/kg, better than 97% of aluminum grades
- High service temperature — 175°C (347 °F), better than 83% of aluminum grades
Limitations
- Limited formability — 5/100, worse than 94% of aluminum grades
- Limited ductility — 1.5%, worse than 91% of aluminum grades
- Poor heat conductor — 105 W/m·K (60.7 BTU/hr·ft·°F), worse than 91% of aluminum grades
- Low electrical conductivity — 27 % IACS, worse than 86% of aluminum grades
- Low fracture toughness — 17 MPa·√m (15.5 ksi·√in), worse than 83% of aluminum grades
344.0-T6 properties
Typical room-temperature values for 344.0-T6; 10 are specific to this condition. Other listed values are 344.0 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
344.0-T6 has a density of 2.75 g/cm³ (0.0994 lb/in³), heavier than 67% of aluminum grades. It melts at 521°C (970 °F).
Mechanical13
344.0-T6 has a yield strength of 210 MPa (30.5 ksi) and a tensile strength of 285 MPa (41.3 ksi) — stronger than 56% of aluminum grades. Elongation at break is 1.5% and the elastic modulus is 74 GPa (10.7 Msi).
Thermal6
344.0-T6 is rated for continuous service to 175°C (347 °F). It conducts heat at 105 W/m·K (60.7 BTU/hr·ft·°F), worse than 91% of aluminum grades. Thermal expansion is 21 µm/m·K (11.7 µin/in·°F).
Electrical3
344.0-T6 conducts electricity at 27 % IACS, worse than 86% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (40/100), worse than 75% of aluminum grades.
Sustainability4
Producing a kilogram of 344.0-T6 takes about 155 MJ of energy and emits 9.5 kg of CO₂ — less than 94% of aluminum grades. Typical recycled content is 75%.
Manufacturability8
344.0-T6's machinability is good (60/100, worse than 51% of aluminum grades); weldability fair (40/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 344.0-T6
Is 344.0 easy to machine?
Machines cleanly with polycrystalline diamond or coated carbide at high speed and generous coolant; eutectic silicon is abrasive so HSS tool life is short.
Can 344.0 be welded?
Weldable by TIG/MIG with 4043/4145 filler for repair, but the copper content raises hot-cracking and porosity risk — preheat 150–200 °C and re-age afterwards.
Can 344.0 be formed, bent or molded?
Permanent-mold and die casting alloy with excellent fluidity and low hot-tear tendency; use Sr or Na modification and controlled iron level for best ductility.
What surface finishes work on 344.0?
Chromate conversion, powder coat or paint for corrosion protection; decorative anodizing turns dark and blotchy because of the high silicon, hard anodize only for wear surfaces.
344.0 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 |
|---|---|---|
| Sieutectic-range silicon gives the fluidity and wear resistance; confirm exact limits against the current AA registration record | 8.5 – 10.5 | 9.5 |
| Cuage-hardening addition, lower than the 2–4 % of 332.0 | 1 – 1.5 | 1.2 |
| MgMg2Si precipitation strengthening in T5/T6 | 0.1 – 0.5 | 0.3 |
| Femax; higher tolerance for die/permanent-mold secondary ingot | ≤ 1.3 | 0.8 |
| Mn | ≤ 0.5 | 0.2 |
| Ni | ≤ 0.5 | — |
| Zn | ≤ 1 | — |
| Timax; grain refinement | ≤ 0.25 | 0.1 |
| Sn | ≤ 0.1 | — |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Al | balance | — |
344.0-T6 — frequently asked
What is 344.0-T6 used for?
344.0-T6 is typically used for pump housings, pistons and small engine components. In short: good fluidity, low hot tearing; moderate strength with wear resistance; better ductility than piston alloys.
What is the yield strength of 344.0-T6?
344.0-T6 has a typical yield strength of 210 MPa (30.5 ksi) and a tensile strength of 285 MPa (41.3 ksi) — stronger than 56% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is 344.0-T6 easy to machine?
Reasonably — machinability is rated good (60/100, worse than 51% of aluminum grades). Machines cleanly with polycrystalline diamond or coated carbide at high speed and generous coolant; eutectic silicon is abrasive so HSS tool life is short.
Can 344.0-T6 be welded?
With care — weldability is rated fair (40/100). Weldable by TIG/MIG with 4043/4145 filler for repair, but the copper content raises hot-cracking and porosity risk — preheat 150–200 °C and re-age afterwards.
What surface finishes work on 344.0-T6?
Chromate conversion, powder coat or paint for corrosion protection; decorative anodizing turns dark and blotchy because of the high silicon, hard anodize only for wear surfaces.
Can 344.0-T6 be formed, bent or molded?
Permanent-mold and die casting alloy with excellent fluidity and low hot-tear tendency; use Sr or Na modification and controlled iron level for best ductility.
What is the maximum service temperature of 344.0-T6?
344.0-T6 is rated for continuous use to about 175°C (347 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 344.0-F and 344.0-T6?
F is the default condition — default stocked condition — as-cast parts where dimensional stability at room temperature and lowest cost matter. T6: highest strength and hardness condition for loaded pump/engine hardware; accept some distortion and higher cost. Yield strength is 125 MPa in F versus 210 MPa in T6.
Sources
- Registration Record of Aluminum Association Alloy Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot (Pink Sheets) — The Aluminum Association (2018)
- ASTM B108 / B85 — Aluminum-Alloy Permanent Mold and Die Castings — ASTM International (2019)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys — ASM International (1993)
- UNS A03440 alloy record — SAE/ASTM Unified Numbering System (2017)
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.