Magnesium Alloy ZM5
ZM5 is a Mg-Al-Zn sand, permanent-mould and die-casting alloy equivalent to AZ91D, the general-purpose workhorse of the Mg-Al-Zn family.
Reference datasheet — ZM5 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
ZM5 tempers and conditions
ZM5 is supplied in 6 conditions, soft to hard. T4 is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Cooled from hot working, cold worked and naturally aged | Low-temperature anneal used to relieve casting or machining stresses and stabilise dimensions before finish machining. | 85 | 160 | 3 | 52 HB | 13 % IACS |
T4Default Solution heat treated and naturally aged | Most-used ZM5 condition: best combination of strength, ductility and impact resistance for structural castings. | 90 | 250 | 8 | 55 HB | 11.5 % IACS |
As fabricated | Lowest-cost condition for lightly loaded housings and covers where dimensional stability matters more than strength. | 90 | 165 | 2.5 | 55 HB | 12 % IACS |
Cooled from hot working and naturally aged | Simple ageing (≈175 °C) of the as-cast part to raise yield strength and hardness without a solution treatment or distortion risk. | 110 | 180 | 2 | 62 HB | 13 % IACS |
Solution heat treated and artificially aged | Choose when maximum yield strength and hardness are needed and low elongation is acceptable. | 140 | 255 | 4 | 70 HB | 13.5 % IACS |
Die cast, as-cast | High-pressure die-cast ZM5/AZ91D: fine chill structure gives higher strength than sand casting, but heat treatment is limited by gas porosity. | 150 | 230 | 3 | 63 HB | 12 % IACS |
What is ZM5?
ZM5 is a Mg-Al-Zn sand, permanent-mould and die-casting alloy equivalent to AZ91D, the general-purpose workhorse of the Mg-Al-Zn family. Conditions on file cover F, T1, T2, T4, T6 and die-cast F, with default as-cast properties of 90 MPa yield, 250 MPa tensile, 8% elongation and 55 HB, thermal conductivity of 51 W/m·K and a machinability score of 95. It is chosen for good fluidity, low hot-tearing tendency and the ability to be welded with AZ92A filler when castings are sound. Service is limited to 120 °C and corrosion protection by conversion coating and paint is mandatory; AM50A/AM60 are the more ductile die-cast alternatives. ZM5 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). ZM5 has a yield strength of 90 MPa (13.1 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 96% of magnesium alloy grades. Elongation at break is 8% and the elastic modulus is 45 GPa (6.53 Msi).
What is ZM5 used for?
- gearbox housings
- engine covers
- electronic enclosures
- automotive brackets
Limitations
- Poor heat conductor — 51 W/m·K (29.5 BTU/hr·ft·°F), worse than 97% of magnesium alloy grades
- Low strength — 90 MPa (13.1 ksi), worse than 96% of magnesium alloy grades
- Low electrical conductivity — 11.5 % IACS, worse than 92% of magnesium alloy grades
- Limited service temperature — 120°C (248 °F), worse than 78% of magnesium alloy grades
ZM5 properties
Typical room-temperature values for ZM5-T4; bars are the position among magnesium alloy grades.
Physical3
ZM5 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).
Mechanical15
ZM5 has a yield strength of 90 MPa (13.1 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 96% of magnesium alloy grades. Elongation at break is 8% and the elastic modulus is 45 GPa (6.53 Msi).
Thermal6
ZM5 is rated for continuous service to 120°C (248 °F). It conducts heat at 51 W/m·K (29.5 BTU/hr·ft·°F), worse than 97% of magnesium alloy grades. Thermal expansion is 26 µm/m·K (14.4 µin/in·°F).
Electrical3
ZM5 conducts electricity at 11.5 % IACS, worse than 92% of magnesium alloy grades.
Chemical & Environmental3
Corrosion resistance is poor (24/100), better than 55% of magnesium alloy grades.
Sustainability4
Producing a kilogram of ZM5 takes about 330 MJ of energy and emits 30 kg of CO₂ — less than 56% of magnesium alloy grades. Typical recycled content is 30%.
Manufacturability8
ZM5's machinability is excellent (95/100, better than 54% of magnesium alloy grades); weldability good (60/100); formability poor (20/100).
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. ZM5 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ZM5
Is ZM5 easy to machine?
Cuts extremely easily with sharp positive-rake tools and high speeds; use dry or mineral-oil cutting (no water-based coolant) and control fine chips — magnesium swarf is a fire hazard.
Can ZM5 be welded?
GTAW/GMAW with AZ92A or AZ101 filler under argon works well; preheat thick sections, avoid welding heavily die-cast (gas-porous) parts, and stress relieve after welding.
Can ZM5 be formed, bent or molded?
A casting alloy — excellent fluidity and low hot-tearing tendency in sand, permanent-mould and high-pressure die casting; melt must be protected with SF6-free cover gas or flux.
ZM5 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 strengthening element (Mg17Al12) | 7.5 – 9 | 8.3 |
| Zn | 0.2 – 0.8 | 0.5 |
| Mnties up Fe, improves corrosion behaviour | 0.15 – 0.5 | 0.3 |
| Siimpurity limit | ≤ 0.3 | |
| Cuimpurity limit; AZ91D high-purity variants ≤0.030 | ≤ 0.1 | |
| FeAZ91D high-purity variants ≤0.005 | ≤ 0.05 | |
| NiAZ91D high-purity variants ≤0.002 | ≤ 0.01 | |
| Beoptional melt-protection addition | 1×10⁻⁴ – 0 | 8×10⁻⁴ |
| Others (total) | ≤ 0.5 | |
| Mg | balance |
What surface finishes work on ZM5?
Always apply chromate/phosphate conversion, Dow 17/HAE anodize or micro-arc oxidation plus paint; avoid direct contact with steel, copper or graphite to prevent galvanic corrosion.
Equivalent designations
Standards and trade names that resolve to Magnesium Alloy ZM5 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- AZ91D
How much does ZM5 cost?
ZM5 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.
ZM5 — frequently asked
What is ZM5 used for?
ZM5 is typically used for gearbox housings, engine covers, electronic enclosures and automotive brackets. In short: general-purpose AZ91 equivalent; best-casting magnesium alloy; weldable with AZ92A filler.
What is the yield strength of ZM5?
ZM5 has a typical yield strength of 90 MPa (13.1 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 96% of magnesium alloy grades. Strength varies by condition: see the 6 listed tempers.
Is ZM5 easy to machine?
Yes — machinability is rated excellent (95/100, better than 54% of magnesium alloy grades). Cuts extremely easily with sharp positive-rake tools and high speeds; use dry or mineral-oil cutting (no water-based coolant) and control fine chips — magnesium swarf is a fire hazard.
Can ZM5 be welded?
Yes — weldability is rated good (60/100). GTAW/GMAW with AZ92A or AZ101 filler under argon works well; preheat thick sections, avoid welding heavily die-cast (gas-porous) parts, and stress relieve after welding.
What surface finishes work on ZM5?
Always apply chromate/phosphate conversion, Dow 17/HAE anodize or micro-arc oxidation plus paint; avoid direct contact with steel, copper or graphite to prevent galvanic corrosion.
Can ZM5 be formed, bent or molded?
A casting alloy — excellent fluidity and low hot-tearing tendency in sand, permanent-mould and high-pressure die casting; melt must be protected with SF6-free cover gas or flux.
What is the maximum service temperature of ZM5?
ZM5 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 ZM5-T4 and ZM5 DC-F?
T4 is the default condition — most-used ZM5 condition: best combination of strength, ductility and impact resistance for structural castings. DC-F: high-pressure die-cast ZM5/AZ91D: fine chill structure gives higher strength than sand casting, but heat treatment is limited by gas porosity. Yield strength is 90 MPa in T4 versus 150 MPa in DC-F.
How much does ZM5 cost?
ZM5 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
- GB/T 1177 (ZM5 / ZMgAl8Zn) — SAC / (2018)
- ASTM B80 / B94 (AZ91C, AZ91D magnesium castings) — ASTM International (2021)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Specialty Handbook: Magnesium and Magnesium Alloys — ASM International (1999)
- ASM Handbook Vol.13B — Corrosion of Magnesium Alloys — ASM International (2005)
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.