Magnesium Alloy MB3-M
Heat-treated state
M = thermomechanically controlled processed
Softest condition for sheet that must be hot-formed, deep drawn or stress-relieved after welding.
Values for the M condition
Other MB3 tempers and conditions
MB3 is listed in 5 conditions; see the grade overview at MB3.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
MThis page Thermomechanically controlled processed | Softest condition for sheet that must be hot-formed, deep drawn or stress-relieved after welding. | 130 | 235 | 16 | 48 HB | 16 % IACS |
Press forged and stress relieved | Die-forged billet for structural fittings; properties similar to extruded but more isotropic. | 155 | 250 | 11 | 54 HB | 16 % IACS |
FDefault As fabricated | Default supply state for MB3 bar, tube and profile; best balance of strength and ductility straight from the press. | 165 | 260 | 12 | 55 HB | 16 % IACS |
Half-hard, cold/warm rolled sheet | Warm-rolled sheet with retained work hardening — pick when flatness and higher yield matter more than bend radius. | 195 | 275 | 8 | 62 HB | 16 % IACS |
Hard (fully cold-worked) sheet/strip | Maximum strength thin sheet for flat, non-formed parts; very limited bendability at room temperature. | 220 | 295 | 5 | 68 HB | 16 % IACS |
What is MB3-M?
MB3-M is MB3 heat treated to M — softest condition for sheet that must be hot-formed, deep drawn or stress-relieved after welding. MB3-M has a yield strength of 130 MPa (18.9 ksi) and a tensile strength of 235 MPa (34.1 ksi) — weaker than 71% of magnesium alloy grades. Elongation at break is 16% and the elastic modulus is 45 GPa (6.53 Msi). MB3-M has a density of 1.79 g/cm³ (0.0647 lb/in³), lighter than 73% of magnesium alloy grades. It melts at 550°C (1,022 °F). F is the default condition FabDigit quotes; M is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 18 MPa·√m (16.4 ksi·√in), better than 97% of magnesium alloy grades
- Ductile — tolerates forming and impact — 16%, better than 92% of magnesium alloy grades
- Forms and bends easily — 35/100, better than 87% of magnesium alloy grades
MB3-M properties
Typical room-temperature values for MB3-M; 21 are specific to this condition. Other listed values are MB3 reference data and may not represent this condition. Bars are the position among magnesium alloy grades.
Physical3
MB3-M has a density of 1.79 g/cm³ (0.0647 lb/in³), lighter than 73% of magnesium alloy grades. It melts at 550°C (1,022 °F).
Mechanical15
MB3-M has a yield strength of 130 MPa (18.9 ksi) and a tensile strength of 235 MPa (34.1 ksi) — weaker than 71% of magnesium alloy grades. Elongation at break is 16% and the elastic modulus is 45 GPa (6.53 Msi).
Thermal6
MB3-M is rated for continuous service to 130°C (266 °F). It conducts heat at 88 W/m·K (50.8 BTU/hr·ft·°F), worse than 54% of magnesium alloy grades. Thermal expansion is 26 µm/m·K (14.4 µin/in·°F).
Electrical3
MB3-M conducts electricity at 16 % IACS, worse than 54% of magnesium alloy grades.
Chemical & Environmental3
Corrosion resistance is poor (22/100), worse than 57% of magnesium alloy grades.
Sustainability4
Producing a kilogram of MB3-M takes about 320 MJ of energy and emits 28 kg of CO₂ — less than 74% of magnesium alloy grades. Typical recycled content is 10%.
Manufacturability8
MB3-M's machinability is excellent (90/100, worse than 95% of magnesium alloy grades); weldability good (65/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with MB3-M
Is MB3 easy to machine?
Machines faster than any other structural metal — high speeds, sharp positive-rake tools, flood mineral oil or dry with generous chip evacuation; never use water-based coolant on fine chips and keep a class-D extinguisher at the machine.
Can MB3 be welded?
GTAW/GMAW with AZ61A or AZ92A filler under argon works well; preheat 150–260 °C on thick sections, clean the oxide immediately before welding and stress-relieve (≈260 °C, 15 min) to avoid SCC.
Can MB3 be formed, bent or molded?
Cold bending is limited to large radii — form, deep draw and stretch at 200–350 °C where elongation rises above 40 %; extrusion ratios and press speeds are lower than for aluminium.
What surface finishes work on MB3?
No sulfuric anodizing; use chromate-free fluoride/phosphate conversion, HAE/Dow 17 or micro-arc oxidation as a base, then epoxy primer plus topcoat, and isolate every steel or copper fastener with nylon washers/sealant.
MB3 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 addition | 3.7 – 4.7 | 4.2 |
| Zn | 0.8 – 1.4 | 1.1 |
| Mnimproves salt-water corrosion resistance by tying up Fe | 0.3 – 0.6 | 0.45 |
| Siimpurity limit | ≤ 0.1 | — |
| Cuimpurity limit | ≤ 0.05 | — |
| Feimpurity limit | ≤ 0.05 | — |
| Niimpurity limit; strongly degrades corrosion | ≤ 0.01 | — |
| Bemelt-protection addition where used | ≤ 0.01 | — |
| Others (each/total)total residuals | ≤ 0.3 | — |
| Mg | balance | — |
MB3-M — frequently asked
What is MB3-M used for?
MB3-M is typically used for extruded structural members, handles and sporting goods frames. In short: higher-strength AZ61 extrusion grade; fastest-machining structural metal; warm forming required.
What is the yield strength of MB3-M?
MB3-M has a typical yield strength of 130 MPa (18.9 ksi) and a tensile strength of 235 MPa (34.1 ksi) — weaker than 71% of magnesium alloy grades. Strength varies by condition: see the 5 listed tempers.
Is MB3-M easy to machine?
Yes — machinability is rated excellent (90/100, worse than 95% of magnesium alloy grades). Machines faster than any other structural metal — high speeds, sharp positive-rake tools, flood mineral oil or dry with generous chip evacuation; never use water-based coolant on fine chips and keep a class-D extinguisher at the machine.
Can MB3-M be welded?
Yes — weldability is rated good (65/100). GTAW/GMAW with AZ61A or AZ92A filler under argon works well; preheat 150–260 °C on thick sections, clean the oxide immediately before welding and stress-relieve (≈260 °C, 15 min) to avoid SCC.
What surface finishes work on MB3-M?
No sulfuric anodizing; use chromate-free fluoride/phosphate conversion, HAE/Dow 17 or micro-arc oxidation as a base, then epoxy primer plus topcoat, and isolate every steel or copper fastener with nylon washers/sealant.
Can MB3-M be formed, bent or molded?
Cold bending is limited to large radii — form, deep draw and stretch at 200–350 °C where elongation rises above 40 %; extrusion ratios and press speeds are lower than for aluminium.
What is the maximum service temperature of MB3-M?
MB3-M is rated for continuous use to about 130°C (266 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between MB3-F and MB3-Y?
F is the default condition — default supply state for MB3 bar, tube and profile; best balance of strength and ductility straight from the press. Y: maximum strength thin sheet for flat, non-formed parts; very limited bendability at room temperature. Yield strength is 165 MPa in F versus 220 MPa in Y.
Sources
- ASM Handbook Vol.2: Properties and Selection — Nonferrous Alloys (Magnesium) — ASM International (1990)
- ASM Specialty Handbook: Magnesium and Magnesium Alloys — ASM International (1999)
- ASM Handbook Vol.5 Surface Engineering / Vol.13B Corrosion — ASM International (2005)
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.