Aluminum B390.0-T7
Temper
AA B390.0 · UNS A23900
T7 = solution heat treated and overaged (stabilized)
Choose for maximum dimensional/thermal stability in hot-running parts, accepting a strength drop from T6.
Values for the T7 condition
Other B390.0 tempers and conditions
B390.0 is listed in 4 conditions; see the grade overview at B390.0.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
FDefault As fabricated | Standard stocked condition for wear-resistant die castings; best dimensional stability at low cost. | 240 | 280 | 1 | 120 HB | 27 % IACS |
T7This page Solution heat treated and overaged (stabilized) | Choose for maximum dimensional/thermal stability in hot-running parts, accepting a strength drop from T6. | 250 | 275 | 1 | 120 HB | 30 % IACS |
Cooled from hot working and artificially aged | Pick when higher hardness and stability are needed without the distortion risk of solution treatment. | 265 | 300 | 1 | 140 HB | 28 % IACS |
Solution heat treated and artificially aged | Highest strength/hardness route, used mainly for permanent-mould, squeeze-cast or thick-wall parts where blistering of die castings is not an issue. | 300 | 320 | 0.8 | 145 HB | 27 % IACS |
What is B390.0-T7?
B390.0-T7 is B390.0 in the T7 temper — choose for maximum dimensional/thermal stability in hot-running parts, accepting a strength drop from T6. B390.0-T7 has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 275 MPa (39.9 ksi) — stronger than 65% of aluminum grades. Elongation at break is 1% and the elastic modulus is 81 GPa (11.7 Msi). B390.0-T7 has a density of 2.73 g/cm³ (0.0986 lb/in³), heavier than 61% of aluminum grades. It melts at 507°C (945 °F). F is the default condition FabDigit quotes; T7 is available on request or by drawing note.
Advantages
- Stiff — 81 GPa (11.7 Msi), better than 96% of aluminum grades
- High service temperature — 230°C (446 °F), better than 95% of aluminum grades
Limitations
- Difficult to machine — 25/100, worse than 96% of aluminum grades
- Limited ductility — 1%, worse than 95% of aluminum grades
- Limited formability — 5/100, worse than 94% of aluminum grades
- Low fracture toughness — 15 MPa·√m (13.7 ksi·√in), worse than 93% of aluminum grades
- Difficult to weld — 20/100, worse than 89% of aluminum grades
B390.0-T7 properties
Typical room-temperature values for B390.0-T7; 22 are specific to this condition. Other listed values are B390.0 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
B390.0-T7 has a density of 2.73 g/cm³ (0.0986 lb/in³), heavier than 61% of aluminum grades. It melts at 507°C (945 °F).
Mechanical12
B390.0-T7 has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 275 MPa (39.9 ksi) — stronger than 65% of aluminum grades. Elongation at break is 1% and the elastic modulus is 81 GPa (11.7 Msi).
Thermal6
B390.0-T7 is rated for continuous service to 230°C (446 °F). It conducts heat at 145 W/m·K (83.8 BTU/hr·ft·°F), better than 53% of aluminum grades. Thermal expansion is 18 µm/m·K (10 µin/in·°F).
Electrical3
B390.0-T7 conducts electricity at 30 % IACS, worse than 73% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (38/100), worse than 79% of aluminum grades.
Sustainability4
Producing a kilogram of B390.0-T7 takes about 205 MJ of energy and emits 12 kg of CO₂ — more than 76% of aluminum grades. Typical recycled content is 90%.
Manufacturability8
B390.0-T7's machinability is poor (25/100, worse than 96% of aluminum grades); weldability poor (20/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with B390.0-T7
Is B390.0 easy to machine?
Treat as an abrasive material: PCD or diamond-coated tooling, high speed / light feed, flood coolant; carbide life is short and honing is standard for bores.
Can B390.0 be welded?
Effectively non-weldable for structural joints — high Si+Cu causes hot cracking and die-cast gas porosity blisters; use mechanical fastening or adhesives.
Can B390.0 be formed, bent or molded?
Die cast only (also permanent mould/squeeze cast); needs controlled melt superheat and moderate holding temperature to keep primary Si finely distributed, and steel dies wear fast.
What surface finishes work on B390.0?
Honing/lapping exposes hard Si for excellent bore wear; anodizing looks dark and mottled, so hard-coat anodize, electroless nickel or paint are preferred.
B390.0 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 |
|---|---|---|
| Siprimary Si particles provide wear resistance | 16 – 18 | 17 |
| Cu | 4 – 5 | 4.5 |
| Mg | 0.45 – 0.65 | 0.55 |
| Ferelaxed vs A390.0 (0.50 max) — enables secondary metal | ≤ 1.3 | 0.8 |
| Mn | ≤ 0.5 | 0.2 |
| Zn | ≤ 1.5 | 0.3 |
| Ni | ≤ 0.1 | — |
| Sn | ≤ 0.1 | — |
| Ti | ≤ 0.2 | — |
| Others (total)each 0.10 max | ≤ 0.2 | — |
| Al | balance | — |
B390.0-T7 — frequently asked
What is B390.0-T7 used for?
B390.0-T7 is typically used for engine components, compressor housings and wear parts. In short: most wear-resistant cast aluminum; hardest die-casting alloy; brittle and non-weldable.
What is the yield strength of B390.0-T7?
B390.0-T7 has a typical yield strength of 250 MPa (36.3 ksi) and a tensile strength of 275 MPa (39.9 ksi) — stronger than 65% of aluminum grades. Strength varies by condition: see the 4 listed tempers.
Is B390.0-T7 easy to machine?
Not especially — machinability is rated poor (25/100, worse than 96% of aluminum grades). Treat as an abrasive material: PCD or diamond-coated tooling, high speed / light feed, flood coolant; carbide life is short and honing is standard for bores.
Can B390.0-T7 be welded?
Not readily — weldability is rated poor (20/100). Effectively non-weldable for structural joints — high Si+Cu causes hot cracking and die-cast gas porosity blisters; use mechanical fastening or adhesives.
What surface finishes work on B390.0-T7?
Honing/lapping exposes hard Si for excellent bore wear; anodizing looks dark and mottled, so hard-coat anodize, electroless nickel or paint are preferred.
Can B390.0-T7 be formed, bent or molded?
Die cast only (also permanent mould/squeeze cast); needs controlled melt superheat and moderate holding temperature to keep primary Si finely distributed, and steel dies wear fast.
What is the maximum service temperature of B390.0-T7?
B390.0-T7 is rated for continuous use to about 230°C (446 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between B390.0-F and B390.0-T6?
F is the default condition — standard stocked condition for wear-resistant die castings; best dimensional stability at low cost. T6: highest strength/hardness route, used mainly for permanent-mould, squeeze-cast or thick-wall parts where blistering of die castings is not an issue. Yield strength is 240 MPa in F versus 300 MPa in T6.
Sources
- ASTM B85/B85M — Aluminum-Alloy Die Castings — ASTM International (2018)
- Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot (Pink Sheets) — The Aluminum Association (2018)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys — ASM International (1993)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
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.