Magnesium Alloy MB3
MB3 is a wrought Mg-Al-Zn alloy comparable to AZ61A, carrying more aluminium than AZ31-type grades for higher strength in extruded bar and profiles, and stocked in F, M, Y2, Y and forged conditions.
Reference datasheet — MB3 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 F condition
MB3 tempers and conditions
MB3 is supplied in 5 conditions, soft to hard. F 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 |
|---|---|---|---|---|---|---|
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?
MB3 is a wrought Mg-Al-Zn alloy comparable to AZ61A, carrying more aluminium than AZ31-type grades for higher strength in extruded bar and profiles, and stocked in F, M, Y2, Y and forged conditions. Engineers use it where a magnesium section must carry load and still machine faster than any other structural metal (machinability score 95). In the default condition it gives 165 MPa yield, 260 MPa tensile, 12 % elongation and 55 HB, with service limited to about 130 °C; cold bending needs large radii, so MB2 sheet is preferred for formed parts. MB3 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). MB3 has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 260 MPa (37.7 ksi) — stronger than 67% of magnesium alloy grades. Elongation at break is 12% and the elastic modulus is 45 GPa (6.53 Msi).
What is MB3 used for?
- extruded structural members
- handles
- sporting goods frames
Advantages
- Tough — resists crack growth — 16 MPa·√m (14.6 ksi·√in), better than 87% of magnesium alloy grades
MB3 properties
Typical room-temperature values for MB3-F; bars are the position among magnesium alloy grades.
Physical3
MB3 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 has a yield strength of 165 MPa (23.9 ksi) and a tensile strength of 260 MPa (37.7 ksi) — stronger than 67% of magnesium alloy grades. Elongation at break is 12% and the elastic modulus is 45 GPa (6.53 Msi).
Thermal6
MB3 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 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 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's machinability is excellent (95/100, better than 54% of magnesium alloy grades); weldability good (60/100); formability poor (25/100).
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. MB3 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with MB3
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.
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 |
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.
Equivalent designations
Standards and trade names that resolve to Magnesium Alloy MB3 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Similar grades
- AZ61A
How much does MB3 cost?
MB3 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.
MB3 — frequently asked
What is MB3 used for?
MB3 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?
MB3 has a typical yield strength of 165 MPa (23.9 ksi) and a tensile strength of 260 MPa (37.7 ksi) — stronger than 67% of magnesium alloy grades. Strength varies by condition: see the 5 listed tempers.
Is MB3 easy to machine?
Yes — machinability is rated excellent (95/100, better than 54% 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 be welded?
Yes — weldability is rated good (60/100). 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?
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 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?
MB3 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.
How much does MB3 cost?
MB3 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
- 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; 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.