Aluminum ZL104-T6
Temper · default condition
GB ZL104 · EN AC-43000 · JIS AC4B
T6 = solution heat treated and artificially aged
Standard structural condition: highest strength and hardness for load-bearing castings such as brackets, pump and gearbox housings.
Values for the T6 condition
Other ZL104 tempers and conditions
ZL104 is listed in 4 conditions; see the grade overview at ZL104.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Cheapest condition for lightly loaded, dimensionally stable housings where heat-treatment distortion is unwanted. | 85 | 175 | 3.5 | 55 HB | 36 % IACS |
Cooled from hot working and artificially aged | Shop practice for dimensional stabilisation of machined permanent-mold parts; modest strength gain over F. | 130 | 200 | 2.5 | 65 HB | 35 % IACS |
Cooled from hot working and naturally aged | Used for permanent-mold parts needing a strength/stability lift without solution-treatment distortion cost. | 150 | 220 | 2 | 68 HB | 35 % IACS |
T6DefaultThis page Solution heat treated and artificially aged | Standard structural condition: highest strength and hardness for load-bearing castings such as brackets, pump and gearbox housings. | 200 | 260 | 3 | 75 HB | 33 % IACS |
What is ZL104-T6?
ZL104-T6 is ZL104 in the T6 temper — standard structural condition: highest strength and hardness for load-bearing castings such as brackets, pump and gearbox housings. ZL104-T6 has a yield strength of 200 MPa (29 ksi) and a tensile strength of 260 MPa (37.7 ksi) — stronger than 53% of aluminum grades. Elongation at break is 3% and the elastic modulus is 71 GPa (10.3 Msi). ZL104-T6 has a density of 2.65 g/cm³ (0.0957 lb/in³), lighter than 90% of aluminum grades. It melts at 557°C (1,035 °F).
Limitations
- Limited formability — 10/100, worse than 80% of aluminum grades
- Limited ductility — 3%, worse than 79% of aluminum grades
- Hard to polish — 45/100, worse than 76% of aluminum grades
ZL104-T6 properties
Typical room-temperature values for ZL104-T6; 11 are specific to this condition. Other listed values are ZL104 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
ZL104-T6 has a density of 2.65 g/cm³ (0.0957 lb/in³), lighter than 90% of aluminum grades. It melts at 557°C (1,035 °F).
Mechanical12
ZL104-T6 has a yield strength of 200 MPa (29 ksi) and a tensile strength of 260 MPa (37.7 ksi) — stronger than 53% of aluminum grades. Elongation at break is 3% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
ZL104-T6 is rated for continuous service to 150°C (302 °F). It conducts heat at 145 W/m·K (83.8 BTU/hr·ft·°F), better than 53% of aluminum grades. Thermal expansion is 21.5 µm/m·K (11.9 µin/in·°F).
Electrical3
ZL104-T6 conducts electricity at 33 % IACS, worse than 57% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), better than 57% of aluminum grades.
Sustainability4
Producing a kilogram of ZL104-T6 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 70%.
Manufacturability8
ZL104-T6's machinability is good (55/100, worse than 59% of aluminum grades); weldability very good (70/100); formability not recommended (10/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ZL104-T6
Is ZL104 easy to machine?
Machines cleanly with PCD or polished-flute carbide at high speed and generous coolant; the eutectic Si is abrasive, so uncoated HSS wears fast and built-up edge appears at low speeds.
Can ZL104 be welded?
Readily TIG/MIG welded or repair-welded with ER4043/ZL104 filler; re-solution + age after welding to restore T6 properties, and avoid 5000-series-type Mg fillers.
Can ZL104 be formed, bent or molded?
Excellent fluidity for thin-wall sand, permanent-mold and low-pressure castings; requires Sr or Na modification plus directional solidification/risering to avoid coarse eutectic and shrinkage porosity.
What surface finishes work on ZL104?
Chromate/ chrome-free conversion coating or powder paint works well; sulfuric or hard anodizing gives only a dark grey non-decorative film because of the high Si, and porosity can cause bleed-out.
ZL104 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 |
|---|---|---|
| SiGB/T 1173 ZAlSi9Mg | 8 – 10.5 | 9 |
| Mgprecipitation strengthening (Mg2Si) | 0.17 – 0.35 | 0.28 |
| Mnneutralises Fe needles | 0.2 – 0.5 | 0.35 |
| Fe≤0.9 % permitted for die/permanent-mold practice in some works standards | ≤ 0.6 | — |
| Cuimpurity limit | ≤ 0.1 | — |
| Znimpurity limit | ≤ 0.25 | — |
| Tigrain refiner residual | ≤ 0.15 | — |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Al | balance | — |
ZL104-T6 — frequently asked
What is ZL104-T6 used for?
ZL104-T6 is typically used for housings, brackets and wheel castings. In short: high-fluidity thin-wall casting; lower cost than AlSi7Mg; protective anodize only.
What is the yield strength of ZL104-T6?
ZL104-T6 has a typical yield strength of 200 MPa (29 ksi) and a tensile strength of 260 MPa (37.7 ksi) — stronger than 53% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is ZL104-T6 easy to machine?
Reasonably — machinability is rated good (55/100, worse than 59% of aluminum grades). Machines cleanly with PCD or polished-flute carbide at high speed and generous coolant; the eutectic Si is abrasive, so uncoated HSS wears fast and built-up edge appears at low speeds.
Can ZL104-T6 be welded?
Yes — weldability is rated very good (70/100). Readily TIG/MIG welded or repair-welded with ER4043/ZL104 filler; re-solution + age after welding to restore T6 properties, and avoid 5000-series-type Mg fillers.
What surface finishes work on ZL104-T6?
Chromate/ chrome-free conversion coating or powder paint works well; sulfuric or hard anodizing gives only a dark grey non-decorative film because of the high Si, and porosity can cause bleed-out.
Can ZL104-T6 be formed, bent or molded?
Excellent fluidity for thin-wall sand, permanent-mold and low-pressure castings; requires Sr or Na modification plus directional solidification/risering to avoid coarse eutectic and shrinkage porosity.
What is the maximum service temperature of ZL104-T6?
ZL104-T6 is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between ZL104-T6 and ZL104-F?
T6 is the default condition — standard structural condition: highest strength and hardness for load-bearing castings such as brackets, pump and gearbox housings. F: cheapest condition for lightly loaded, dimensionally stable housings where heat-treatment distortion is unwanted. Yield strength is 200 MPa in T6 versus 85 MPa in F.
Sources
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys (359.0 / A356-class data) — ASM International (1990)
- EN 1706 — Aluminium castings, EN AC-43000 (AlSi10Mg) — CEN (2020)
- JIS H5202 — Aluminium alloy castings (AC4B) — JSA (2010)
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.