Magnesium Alloy ML5
ML5 is a GOST Mg-Al-Zn sand-casting alloy equivalent to AZ91C, widely used for aerospace and machinery castings and available in F, T1, T2, T4 and T6.
Reference datasheet — ML5 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the T4 condition
ML5 tempers and conditions
ML5 is supplied in 5 conditions, soft to hard. T4 is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Cooled from hot working, cold worked and naturally aged | Use when residual stress from casting, welding or heavy machining must be removed and strength is secondary. | 85 | 160 | 3 | 52 HB | 13 % IACS |
T4Default Solution heat treated and naturally aged | Standard aerospace condition for ML5 castings — best combination of strength, ductility and impact resistance. | 95 | 260 | 8 | 60 HB | 72 W/m·K |
As fabricated | Lowest cost condition for lightly loaded housings and covers where ductility is not critical. | 95 | 165 | 2.5 | 55 HB | 72 W/m·K |
Cooled from hot working and naturally aged | Simple ageing of the as-cast part to raise yield strength and stabilise dimensions without a solution treatment. | 110 | 195 | 2 | 65 HB | 12.5 % IACS |
Solution heat treated and artificially aged | Pick when maximum yield strength, hardness and dimensional stability matter more than ductility. | 135 | 275 | 4 | 70 HB | 72 W/m·K |
What is ML5?
ML5 is a GOST Mg-Al-Zn sand-casting alloy equivalent to AZ91C, widely used for aerospace and machinery castings and available in F, T1, T2, T4 and T6. It offers the highest machinability in this family at score 98, with 95 MPa yield, 260 MPa tensile, 8% elongation, 60 HB and 72 W/m·K thermal conductivity in the default condition, plus good mould fluidity. Service is limited to 120 °C, bare surfaces need conversion coating and paint, and MC3 (ZK51A) is the alternative when higher cast yield strength is required. ML5 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). ML5 has a yield strength of 95 MPa (13.8 ksi) and a tensile strength of 260 MPa (37.7 ksi) — weaker than 93% of magnesium alloy grades. Elongation at break is 8% and the elastic modulus is 45 GPa (6.53 Msi).
What is ML5 used for?
- gearbox housings
- aircraft fitting castings
- machinery housings
Limitations
- Low strength — 95 MPa (13.8 ksi), worse than 93% 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
ML5 properties
Typical room-temperature values for ML5-T4; bars are the position among magnesium alloy grades.
Physical3
ML5 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).
Mechanical13
ML5 has a yield strength of 95 MPa (13.8 ksi) and a tensile strength of 260 MPa (37.7 ksi) — weaker than 93% of magnesium alloy grades. Elongation at break is 8% and the elastic modulus is 45 GPa (6.53 Msi).
Thermal6
ML5 is rated for continuous service to 120°C (248 °F). It conducts heat at 72 W/m·K (41.6 BTU/hr·ft·°F), worse than 69% of magnesium alloy grades. Thermal expansion is 26 µm/m·K (14.4 µin/in·°F).
Electrical3
ML5 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 ML5 takes about 320 MJ of energy and emits 30 kg of CO₂ — less than 74% of magnesium alloy grades. Typical recycled content is 30%.
Manufacturability8
ML5's machinability is excellent (98/100, better than 96% of magnesium alloy grades); weldability good (65/100); formability poor (15/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the magnesium alloy family
Yield strength against density for every magnesium alloy grade FabDigit runs. ML5 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ML5
Is ML5 easy to machine?
Outstanding machinability with sharp, high-rake tooling and high speeds; use dry or mineral-oil cutting (never water-based) and manage fine chips against fire risk.
Can ML5 be welded?
Readily GTAW/GMAW welded with AZ92A or AZ101 filler in argon; preheat thick sections and stress-relieve or re-solution treat after welding.
Can ML5 be formed, bent or molded?
Sand and permanent-mould casting alloy with good fluidity and low hot-tearing tendency; melt must be flux- or SF6/SO2-protected and grain refined by superheat.
ML5 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 |
|---|---|---|
| Alprimary strengthening element (Mg17Al12) | 7.5 – 9 | 8.3 |
| Zn | 0.2 – 0.8 | 0.5 |
| Mncontrols Fe for corrosion resistance | 0.15 – 0.5 | 0.3 |
| Siimpurity | ≤ 0.25 | |
| Cuimpurity | ≤ 0.1 | |
| Feimpurity | ≤ 0.06 | |
| Niimpurity, strongly harmful to corrosion | ≤ 0.01 | |
| Bemelt oxidation inhibitor | ≤ 0 | |
| Mg | balance |
What surface finishes work on ML5?
No conventional anodizing — use chromate/Dow 17/HAE conversion coatings or plasma-electrolytic oxidation, then epoxy primer and paint; isolate from steel and aluminium fasteners to avoid galvanic attack.
Equivalent designations
Standards and trade names that resolve to Magnesium Alloy ML5 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- AZ91C
How much does ML5 cost?
ML5 is a standard-cost magnesium alloy ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
ML5 — frequently asked
What is ML5 used for?
ML5 is typically used for gearbox housings, aircraft fitting castings and machinery housings. In short: best-machining cast magnesium; weldable AZ91C-type casting; heat-treatable to T6.
What is the yield strength of ML5?
ML5 has a typical yield strength of 95 MPa (13.8 ksi) and a tensile strength of 260 MPa (37.7 ksi) — weaker than 93% of magnesium alloy grades. Strength varies by condition: see the 5 listed tempers.
Is ML5 easy to machine?
Yes — machinability is rated excellent (98/100, better than 96% of magnesium alloy grades). Outstanding machinability with sharp, high-rake tooling and high speeds; use dry or mineral-oil cutting (never water-based) and manage fine chips against fire risk.
Can ML5 be welded?
Yes — weldability is rated good (65/100). Readily GTAW/GMAW welded with AZ92A or AZ101 filler in argon; preheat thick sections and stress-relieve or re-solution treat after welding.
What surface finishes work on ML5?
No conventional anodizing — use chromate/Dow 17/HAE conversion coatings or plasma-electrolytic oxidation, then epoxy primer and paint; isolate from steel and aluminium fasteners to avoid galvanic attack.
Can ML5 be formed, bent or molded?
Sand and permanent-mould casting alloy with good fluidity and low hot-tearing tendency; melt must be flux- or SF6/SO2-protected and grain refined by superheat.
What is the maximum service temperature of ML5?
ML5 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 ML5-T4 and ML5-T6?
T4 is the default condition — standard aerospace condition for ML5 castings — best combination of strength, ductility and impact resistance. T6: pick when maximum yield strength, hardness and dimensional stability matter more than ductility. Yield strength is 95 MPa in T4 versus 135 MPa in T6.
How much does ML5 cost?
ML5 is a standard-cost magnesium alloy ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- GOST 2856-79 Magnesium casting alloys — grades — Gosstandart (1979)
- ASTM B80 / ASTM B403 Magnesium-Alloy Sand and Investment Castings (AZ91C/AZ91E) — ASTM International (2020)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Specialty Handbook: Magnesium and Magnesium Alloys — ASM International (1999)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.