Magnesium Alloy MB2
MB2 is a wrought Mg-Al-Zn alloy equivalent to AZ31B, strengthened by solid solution and cold work rather than aging, and stocked in O, H24, H26, as-extruded and as-forged conditions.
Reference datasheet — MB2 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 H24 condition
MB2 tempers and conditions
MB2 is supplied in 5 conditions, soft to hard. H24 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 |
|---|---|---|---|---|---|---|
Annealed | Softest, most formable condition — choose for deep hot forming, stretch forming and welded assemblies. | 150 | 245 | 21 | 49 HB | 96 W/m·K |
as-forged / die-forged ( , 300–400 °C) | For net-shape hot-forged brackets and housings; grain refinement gives isotropic mid-range strength. | 165 | 260 | 12 | 52 HB | — |
as-extruded bar, rod, tube and profile | Default condition for MB2 extrusions — good longitudinal strength, moderate anisotropy (low compressive yield). | 170 | 260 | 15 | 49 HB | 96 W/m·K |
H24Default Strain hardened and partially annealed, half hard | Standard stocked sheet condition: best balance of strength, flatness and residual formability. | 220 | 290 | 15 | 73 HB | 96 W/m·K |
Strain hardened and partially annealed, three-quarter hard | Pick when maximum sheet strength/stiffness-per-thickness is needed and forming is minimal. | 235 | 300 | 11 | 77 HB | — |
Supply forms, finishes and certifications
Ways MB2 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
O-plate-stress-relieved | O + stress relief | Supply form |
What is MB2?
MB2 is a wrought Mg-Al-Zn alloy equivalent to AZ31B, strengthened by solid solution and cold work rather than aging, and stocked in O, H24, H26, as-extruded and as-forged conditions. It is chosen for low-density sheet, plate, extrusions and forgings where machinability (score 95) and 96 W/m·K thermal conductivity matter. The limits are modest strength (220 MPa yield, 290 MPa tensile, 15 % elongation, 73 HB / 47 HRB), a 120 °C service ceiling, poor cold formability (score 30) and a mandatory protective coating system. MB3 (AZ61A) is the nearest higher-strength option. MB2 has a density of 1.78 g/cm³ (0.0643 lb/in³), lighter than 78% of magnesium alloy grades. It melts at 566°C (1,051 °F). MB2 has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 290 MPa (42.1 ksi) — stronger than 91% of magnesium alloy grades. Elongation at break is 15% and the elastic modulus is 45 GPa (6.53 Msi).
What is MB2 used for?
- sheet stock
- extruded structural sections
- electronics housings
Advantages
- Tough — resists crack growth — 18 MPa·√m (16.4 ksi·√in), better than 97% of magnesium alloy grades
- High strength — 220 MPa (31.9 ksi), better than 91% of magnesium alloy grades
- Ductile — tolerates forming and impact — 15%, better than 87% of magnesium alloy grades
- Forms and bends easily — 30/100, better than 82% of magnesium alloy grades
Limitations
- Limited service temperature — 120°C (248 °F), worse than 78% of magnesium alloy grades
MB2 properties
Typical room-temperature values for MB2-H24; bars are the position among magnesium alloy grades.
Physical3
MB2 has a density of 1.78 g/cm³ (0.0643 lb/in³), lighter than 78% of magnesium alloy grades. It melts at 566°C (1,051 °F).
Mechanical15
MB2 has a yield strength of 220 MPa (31.9 ksi) and a tensile strength of 290 MPa (42.1 ksi) — stronger than 91% of magnesium alloy grades. Elongation at break is 15% and the elastic modulus is 45 GPa (6.53 Msi).
Thermal6
MB2 is rated for continuous service to 120°C (248 °F). It conducts heat at 96 W/m·K (55.5 BTU/hr·ft·°F), better than 50% of magnesium alloy grades. Thermal expansion is 26 µm/m·K (14.4 µin/in·°F).
Electrical3
MB2 conducts electricity at 19 % IACS, better than 53% of magnesium alloy grades.
Chemical & Environmental3
Corrosion resistance is poor (22/100), worse than 57% of magnesium alloy grades.
Sustainability4
Producing a kilogram of MB2 takes about 340 MJ of energy and emits 33 kg of CO₂ — more than 59% of magnesium alloy grades. Typical recycled content is 25%.
Manufacturability8
MB2's machinability is excellent (95/100, better than 54% of magnesium alloy grades); weldability very good (70/100); formability poor (30/100).
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. MB2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with MB2
Is MB2 easy to machine?
Outstanding machinability — high speeds, sharp positive-rake tools, no coolant mist with water where avoidable; chips and fines are flammable, use dry vacuum collection and Class D extinguishers.
Can MB2 be welded?
Readily GTAW/GMAW welded under Ar or Ar-He with AZ61A/AZ92A filler; clean oxide first, avoid brittle Fe/Ni contamination, stress-relieve welded H24 parts at ~150 °C to prevent SCC.
Can MB2 be formed, bent or molded?
Cold forming limited (large bend radii, 5–7 t); form at 230–300 °C where elongation exceeds 50 %, and hot-size or hot-draw deep parts.
MB2 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 / solid-solution | 3 – 4 | 3.5 |
| Zn | 0.2 – 0.8 | 0.5 |
| Mnties up Fe, improves corrosion | 0.15 – 0.5 | 0.3 |
| Siimpurity limit | ≤ 0.1 | |
| Cuimpurity limit | ≤ 0.05 | |
| Feimpurity limit | ≤ 0.05 | |
| Niimpurity limit, critical for corrosion | ≤ 0.01 | |
| Bemelt-protection addition, optional | ≤ 0.01 | |
| Others (each)total ≤ 0.30 % | ≤ 0.05 | |
| Mg | balance |
What surface finishes work on MB2?
Do not use aluminium sulfuric anodize; apply chromate or chrome-free conversion coating, HAE/Dow 17 anodic coating or MAO, then epoxy prime and topcoat; isolate from steel/aluminium fasteners to avoid galvanic attack.
Equivalent designations
Standards and trade names that resolve to Magnesium Alloy MB2 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- AZ31B
How much does MB2 cost?
MB2 is a premium-cost magnesium alloy ($$$), cheaper than about 51% 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.
MB2 — frequently asked
What is MB2 used for?
MB2 is typically used for sheet stock, extruded structural sections and electronics housings. In short: most common wrought magnesium; weldable magnesium sheet grade; very high machinability.
What is the yield strength of MB2?
MB2 has a typical yield strength of 220 MPa (31.9 ksi) and a tensile strength of 290 MPa (42.1 ksi) — stronger than 91% of magnesium alloy grades. Strength varies by condition: see the 5 listed tempers.
Is MB2 easy to machine?
Yes — machinability is rated excellent (95/100, better than 54% of magnesium alloy grades). Outstanding machinability — high speeds, sharp positive-rake tools, no coolant mist with water where avoidable; chips and fines are flammable, use dry vacuum collection and Class D extinguishers.
Can MB2 be welded?
Yes — weldability is rated very good (70/100). Readily GTAW/GMAW welded under Ar or Ar-He with AZ61A/AZ92A filler; clean oxide first, avoid brittle Fe/Ni contamination, stress-relieve welded H24 parts at ~150 °C to prevent SCC.
What surface finishes work on MB2?
Do not use aluminium sulfuric anodize; apply chromate or chrome-free conversion coating, HAE/Dow 17 anodic coating or MAO, then epoxy prime and topcoat; isolate from steel/aluminium fasteners to avoid galvanic attack.
Can MB2 be formed, bent or molded?
Cold forming limited (large bend radii, 5–7 t); form at 230–300 °C where elongation exceeds 50 %, and hot-size or hot-draw deep parts.
What is the maximum service temperature of MB2?
MB2 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 MB2-H24 and MB2-O?
H24 is the default condition — standard stocked sheet condition: best balance of strength, flatness and residual formability. O: softest, most formable condition — choose for deep hot forming, stretch forming and welded assemblies. Yield strength is 220 MPa in H24 versus 150 MPa in O.
How much does MB2 cost?
MB2 is a premium-cost magnesium alloy ($$$), cheaper than about 51% 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
- ASTM B90/B90M Magnesium-Alloy Sheet and Plate — ASTM (2015)
- ASTM B107/B107M Magnesium-Alloy Extruded Bars, Rods, Profiles, Tubes and Wire — ASTM (2013)
- ASM Handbook Vol.2 — Properties of Magnesium Alloys (AZ31B) — ASM International (1990)
- Magnesium and Magnesium Alloys, ASM Specialty Handbook — ASM International (1999)
- MMPDS / MIL-HDBK-5 magnesium sheet allowables (AZ31B) — FAA/Battelle (2020)
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.