Aluminum EN AC-42100-T7
Temper
EN AC-42100
T7 = solution heat treated and overaged (stabilized)
Over-aged for dimensional stability and reduced residual stress at slightly elevated service temperature, at the cost of yield strength.
Values for the T7 condition
Other EN AC-42100 tempers and conditions
EN AC-42100 is listed in 6 conditions; see the grade overview at EN AC-42100.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Lowest-cost condition for non-structural or dimensionally critical parts where no heat treatment is applied. | 85 | 170 | 4 | 55 HB | 43 % IACS |
Cooled from hot working and artificially aged | Modest strength gain without solution treatment; used when distortion from quenching must be avoided. | 125 | 195 | 3 | 65 HB | 41 % IACS |
T7This page Solution heat treated and overaged (stabilized) | Over-aged for dimensional stability and reduced residual stress at slightly elevated service temperature, at the cost of yield strength. | 180 | 225 | 6 | 70 HB | 42 % IACS |
Solution heat treated and under-aged | Choose when energy absorption, riveting/crimping or crash ductility matters more than peak yield strength (chassis and safety-critical castings). | 195 | 265 | 10 | 85 HB | 42 % IACS |
T6 variant, underaged | Long solution soak with fine Si spheroidisation — higher strength and ductility together, used for premium permanent-mould aerospace castings. | 207 | 283 | 10 | 90 HB | 40 % IACS |
T6Default Solution heat treated and artificially aged | Standard structural condition: maximum strength and hardness with acceptable ductility — the default for wheels, knuckles and aerospace castings. | 230 | 295 | 6 | 95 HB | 39 % IACS |
What is EN AC-42100-T7?
EN AC-42100-T7 is EN AC-42100 in the T7 temper — over-aged for dimensional stability and reduced residual stress at slightly elevated service temperature, at the cost of yield strength. EN AC-42100-T7 has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 54% of aluminum grades. Elongation at break is 6% and the elastic modulus is 72.4 GPa (10.5 Msi). EN AC-42100-T7 has a density of 2.68 g/cm³ (0.0968 lb/in³), lighter than 72% of aluminum grades. It melts at 557°C (1,035 °F). T6 is the default condition FabDigit quotes; T7 is available on request or by drawing note.
Advantages
- Low embodied carbon — 10.5 kg CO₂/kg, better than 95% of aluminum grades
- High service temperature — 175°C (347 °F), better than 83% of aluminum grades
- High electrical conductivity — 42 % IACS, better than 81% of aluminum grades
EN AC-42100-T7 properties
Typical room-temperature values for EN AC-42100-T7; 20 are specific to this condition. Other listed values are EN AC-42100 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
EN AC-42100-T7 has a density of 2.68 g/cm³ (0.0968 lb/in³), lighter than 72% of aluminum grades. It melts at 557°C (1,035 °F).
Mechanical14
EN AC-42100-T7 has a yield strength of 180 MPa (26.1 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 54% of aluminum grades. Elongation at break is 6% and the elastic modulus is 72.4 GPa (10.5 Msi).
Thermal6
EN AC-42100-T7 is rated for continuous service to 175°C (347 °F). It conducts heat at 159 W/m·K (91.9 BTU/hr·ft·°F), better than 74% of aluminum grades. Thermal expansion is 21.5 µm/m·K (11.9 µin/in·°F).
Electrical3
EN AC-42100-T7 conducts electricity at 42 % IACS, better than 81% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is good (66/100), better than 73% of aluminum grades.
Sustainability4
Producing a kilogram of EN AC-42100-T7 takes about 155 MJ of energy and emits 10.5 kg of CO₂ — less than 94% of aluminum grades. Typical recycled content is 30%.
Manufacturability8
EN AC-42100-T7's machinability is good (56/100, worse than 55% of aluminum grades); weldability very good (75/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with EN AC-42100-T7
Is EN AC-42100 easy to machine?
Machines freely with sharp PCD or polished-flute carbide tools, high speed and flood coolant; eutectic Si is abrasive so uncoated HSS wears quickly.
Can EN AC-42100 be welded?
Readily TIG/MIG welded with ER4043 or ER4047 (ER5356 for anodised colour match is not recommended); re-solution + age locally softened T6 castings for full properties.
Can EN AC-42100 be formed, bent or molded?
Excellent fluidity for sand, permanent-mould, low-pressure and investment casting; Sr modification plus Al-Ti-B grain refinement and directional solidification give low porosity and high T6 ductility. Not a wrought alloy — no cold forming.
What surface finishes work on EN AC-42100?
Chromate-free conversion coating, primer/paint or powder coat are the usual finishes; sulphuric or hard anodizing gives a dark grey, less uniform layer due to 7% Si; shot peening raises fatigue life.
EN AC-42100 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 former, Sr or Na modified in practice | 6.5 – 7.5 | 7 |
| MgMg2Si precipitation hardening | 0.25 – 0.45 | 0.35 |
| Fe0.15 max for sand/permanent mould premium quality | ≤ 0.19 | 0.12 |
| Cu | ≤ 0.05 | — |
| Mn | ≤ 0.1 | — |
| Zn | ≤ 0.07 | — |
| Tigrain refinement (Al-Ti-B) | 0.08 – 0.25 | 0.13 |
| Others (each) | ≤ 0.03 | — |
| Others (total) | ≤ 0.1 | — |
| Al | balance | — |
EN AC-42100-T7 — frequently asked
What is EN AC-42100-T7 used for?
EN AC-42100-T7 is typically used for wheels, suspension components, engine housings and aerospace structural castings. In short: workhorse Al-Si-Mg casting alloy; weldable and heat treatable; good corrosion resistance.
What is the yield strength of EN AC-42100-T7?
EN AC-42100-T7 has a typical yield strength of 180 MPa (26.1 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 54% of aluminum grades. Strength varies by condition: see the 6 listed tempers.
Is EN AC-42100-T7 easy to machine?
Reasonably — machinability is rated good (56/100, worse than 55% of aluminum grades). Machines freely with sharp PCD or polished-flute carbide tools, high speed and flood coolant; eutectic Si is abrasive so uncoated HSS wears quickly.
Can EN AC-42100-T7 be welded?
Yes — weldability is rated very good (75/100). Readily TIG/MIG welded with ER4043 or ER4047 (ER5356 for anodised colour match is not recommended); re-solution + age locally softened T6 castings for full properties.
What surface finishes work on EN AC-42100-T7?
Chromate-free conversion coating, primer/paint or powder coat are the usual finishes; sulphuric or hard anodizing gives a dark grey, less uniform layer due to 7% Si; shot peening raises fatigue life.
Can EN AC-42100-T7 be formed, bent or molded?
Excellent fluidity for sand, permanent-mould, low-pressure and investment casting; Sr modification plus Al-Ti-B grain refinement and directional solidification give low porosity and high T6 ductility. Not a wrought alloy — no cold forming.
What is the maximum service temperature of EN AC-42100-T7?
EN AC-42100-T7 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 EN AC-42100-T6 and EN AC-42100-F?
T6 is the default condition — standard structural condition: maximum strength and hardness with acceptable ductility — the default for wheels, knuckles and aerospace castings. F: lowest-cost condition for non-structural or dimensionally critical parts where no heat treatment is applied. Yield strength is 230 MPa in T6 versus 85 MPa in F.
Sources
- EN 1706 Aluminium and aluminium alloys — Castings — Chemical composition and mechanical properties — CEN (2020)
- ASTM B26/B26M & B108/B108M (A356.0 sand and permanent mould castings) — ASTM International (2022)
- GB/T 1173 (ZL101A) — SAC (2013)
- ASM Handbook Vol. 2: Properties and Selection — Nonferrous Alloys — ASM International (1990)
- ASM Specialty Handbook: Aluminum and Aluminum Alloys — ASM International (1993)
- Aluminum Association Teal Sheets — Designations and chemical composition limits for aluminum alloys in the form of castings and ingot — The Aluminum Association (2019)
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.