Magnesium Alloy MC1-T4
Temper
JIS MC1
T4 = solution heat treated and naturally aged
Pick when maximum ductility and impact tolerance are needed from a casting, at the cost of low yield strength.
Values for the T4 condition
Other MC1 tempers and conditions
MC1 is listed in 4 conditions; see the grade overview at MC1.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
T4This page Solution heat treated and naturally aged | Pick when maximum ductility and impact tolerance are needed from a casting, at the cost of low yield strength. | 90 | 275 | 12 | 55 HB | 55 W/m·K |
As fabricated | Cheapest condition for low-stress covers and housings where dimensional stability of the as-cast part matters more than strength. | 97 | 165 | 2.5 | 60 HB | — |
Cooled from hot working and artificially aged | Low-distortion alternative when a modest hardness/stability gain is wanted without a full solution soak and quench. | 110 | 165 | 2 | 65 HB | 12.5 % IACS |
T6Default Solution heat treated and artificially aged | Standard supply condition: best combination of yield strength and hardness for load-bearing Mg castings; ductility and toughness are low. | 145 | 275 | 4 | 70 HB | 72 W/m·K |
What is MC1-T4?
MC1-T4 is MC1 in the T4 temper — pick when maximum ductility and impact tolerance are needed from a casting, at the cost of low yield strength. MC1-T4 has a yield strength of 90 MPa (13.1 ksi) and a tensile strength of 275 MPa (39.9 ksi) — weaker than 96% of magnesium alloy grades. Elongation at break is 12% and the elastic modulus is 45 GPa (6.53 Msi). MC1-T4 has a density of 1.81 g/cm³ (0.0654 lb/in³), heavier than 58% of magnesium alloy grades. It melts at 470°C (878 °F). T6 is the default condition FabDigit quotes; T4 is available on request or by drawing note.
Limitations
- Low fracture toughness — 11 MPa·√m (10 ksi·√in), worse than 100% of magnesium alloy grades
- Low strength — 90 MPa (13.1 ksi), worse than 96% of magnesium alloy grades
- Poor heat conductor — 55 W/m·K (31.8 BTU/hr·ft·°F), worse than 90% of magnesium alloy grades
- Limited service temperature — 120°C (248 °F), worse than 78% of magnesium alloy grades
- Low electrical conductivity — 12 % IACS, worse than 78% of magnesium alloy grades
MC1-T4 properties
Typical room-temperature values for MC1-T4; 11 are specific to this condition. Other listed values are MC1 reference data and may not represent this condition. Bars are the position among magnesium alloy grades.
Physical3
MC1-T4 has a density of 1.81 g/cm³ (0.0654 lb/in³), heavier than 58% of magnesium alloy grades. It melts at 470°C (878 °F).
Mechanical12
MC1-T4 has a yield strength of 90 MPa (13.1 ksi) and a tensile strength of 275 MPa (39.9 ksi) — weaker than 96% of magnesium alloy grades. Elongation at break is 12% and the elastic modulus is 45 GPa (6.53 Msi).
Thermal6
MC1-T4 is rated for continuous service to 120°C (248 °F). It conducts heat at 55 W/m·K (31.8 BTU/hr·ft·°F), worse than 90% of magnesium alloy grades. Thermal expansion is 26 µm/m·K (14.4 µin/in·°F).
Electrical3
MC1-T4 conducts electricity at 12 % IACS, worse than 78% of magnesium alloy grades.
Chemical & Environmental3
Corrosion resistance is poor (20/100), worse than 77% of magnesium alloy grades.
Sustainability4
Producing a kilogram of MC1-T4 takes about 310 MJ of energy and emits 30 kg of CO₂ — less than 85% of magnesium alloy grades. Typical recycled content is 30%.
Manufacturability8
MC1-T4's machinability is excellent (95/100, better than 54% of magnesium alloy grades); weldability very good (70/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with MC1-T4
Is MC1 easy to machine?
Outstanding machinability at high speed with sharp positive-rake tools and light or dry cutting — but chips/fines are flammable, so use flood mineral oil (never water-based) and keep a class-D extinguisher.
Can MC1 be welded?
GTAW/GMAW in argon with AZ92A or AZ101 filler works well; preheat thick sections, avoid moisture, and re-solution/age T6 parts after major repair welds.
Can MC1 be formed, bent or molded?
Excellent sand and permanent-mould castability with good fluidity and low hot-tear tendency; use SF6-free cover gas or flux, generous fillets, chills for feeding, and expect ~1.3 % solidification shrinkage.
What surface finishes work on MC1?
Not sulphuric-anodizable: apply chromate/fluoride or Dow 17/HAE conversion coat, or PEO coating, followed by epoxy primer and topcoat; isolate from steel and copper fasteners to avoid rapid galvanic attack.
MC1 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 |
|---|---|---|
| Alprincipal strengthener (Mg17Al12 precipitation) | 8.1 – 9.3 | 8.7 |
| Zn | 0.4 – 1 | 0.7 |
| Mn0.13 % min for corrosion control | 0.13 – 0.35 | 0.2 |
| Si | ≤ 0.3 | — |
| Cu | ≤ 0.1 | — |
| Nimax — key corrosion impurity | ≤ 0.01 | — |
| Fenot always specified for the C-type alloy; high-purity E-type limits are tighter | ≤ 0.03 | — |
| Others (each)0.30 % total | ≤ 0.1 | — |
| Mg | balance | — |
MC1-T4 — frequently asked
What is MC1-T4 used for?
MC1-T4 is typically used for automotive housings, power tool bodies and cast brackets. In short: workhorse magnesium casting alloy; weld-repairable sand casting; heat-treatable to T6.
What is the yield strength of MC1-T4?
MC1-T4 has a typical yield strength of 90 MPa (13.1 ksi) and a tensile strength of 275 MPa (39.9 ksi) — weaker than 96% of magnesium alloy grades. Strength varies by condition: see the 4 listed tempers.
Is MC1-T4 easy to machine?
Yes — machinability is rated excellent (95/100, better than 54% of magnesium alloy grades). Outstanding machinability at high speed with sharp positive-rake tools and light or dry cutting — but chips/fines are flammable, so use flood mineral oil (never water-based) and keep a class-D extinguisher.
Can MC1-T4 be welded?
Yes — weldability is rated very good (70/100). GTAW/GMAW in argon with AZ92A or AZ101 filler works well; preheat thick sections, avoid moisture, and re-solution/age T6 parts after major repair welds.
What surface finishes work on MC1-T4?
Not sulphuric-anodizable: apply chromate/fluoride or Dow 17/HAE conversion coat, or PEO coating, followed by epoxy primer and topcoat; isolate from steel and copper fasteners to avoid rapid galvanic attack.
Can MC1-T4 be formed, bent or molded?
Excellent sand and permanent-mould castability with good fluidity and low hot-tear tendency; use SF6-free cover gas or flux, generous fillets, chills for feeding, and expect ~1.3 % solidification shrinkage.
What is the maximum service temperature of MC1-T4?
MC1-T4 is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between MC1-T6 and MC1-T4?
T6 is the default condition — standard supply condition: best combination of yield strength and hardness for load-bearing Mg castings; ductility and toughness are low. T4: pick when maximum ductility and impact tolerance are needed from a casting, at the cost of low yield strength. Yield strength is 145 MPa in T6 versus 90 MPa in T4.
Sources
- JIS H 5203 Magnesium Alloy Castings (MC series) — Japanese Standards Association (2006)
- ASTM B80 Magnesium-Alloy Sand Castings — ASTM International (2020)
- ASTM B199 Magnesium-Alloy Permanent Mold Castings — ASTM International (2019)
- ASM Specialty Handbook: Magnesium and Magnesium Alloys — ASM International (1999)
- 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.