Magnesium Alloy MB1-O vs MB1-R
Magnesium Alloy · MB1 temper comparison
MB1-O and MB1-R are two conditions of the same magnesium alloy grade, MB1: O (annealed) versus R (hot rolled sheet/plate). The chemistry is identical, so every difference below comes from the condition. MB1-R is the stronger of the two: yield strength 140 MPa (20.3 ksi) against 105 MPa (15.2 ksi) for MB1-O, about 33% more; tensile strength follows at 240 MPa (34.8 ksi) vs 225 MPa (32.6 ksi). In exchange, MB1-O is the more ductile: elongation 12% versus 9% for MB1-R, and MB1-R is harder (45 HB vs 40 HB).
MB1-OChoose it when the part is bent, formed or impact-loaded.
MB1-RChoose it when strength drives the design.
MB1-O vs MB1-R: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all magnesium alloy grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all magnesium alloy grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 45 GPa6.5 Msi · Shear Modulus 17 GPa2.5 Msi · Bulk Modulus 36 GPa5.2 Msi · Poisson's Ratio 0.35 · Fracture Toughness (K_IC) 15 MPa·√m13.7 ksi·√in
Physical
Density and transition temperatures.
Same in both: Density 1.76 g/cm³0.06 lb/in³ · Melting Point (Solidus) 648°C1,198 °F · Liquidus Temperature 651°C1,204 °F
Thermal
How each material carries heat and how hot it can run.
Same in both: Thermal Conductivity 138 W/m·K79.7 BTU/hr·ft·°F · Specific Heat Capacity 1,000 J/kg·K0.24 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 26 µm/m·K14.4 µin/in·°F · Latent Heat of Fusion 370 J/g159 BTU/lb · Max Service Temperature (continuous) 150°C302 °F · Min Service Temperature -60°C-76 °F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 33 % IACS · Electrical Resistivity 5.2×10⁻⁸ Ω·m2.05 µΩ·in
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -1.6 V · Corrosion Resistance 22 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Formability (cold)
Same in both: Machinability Rating (AISI 1212 = 100 %) 500% · Brazeability / Solderability 25 / 100 · Polishability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 300 MJ/kg128,977 BTU/lb · Embodied Carbon (primary production) 28 kg CO₂/kg · Embodied Water 500 L/kg59.9 gal/lb · Typical Recycled Content 25%
Strength versus weight
Yield strength against density for every magnesium alloy grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
MB1-O vs MB1-R — frequently asked
Is MB1-R stronger than MB1-O?
Yes. MB1-R has a typical yield strength of 140 MPa (20.3 ksi) against 105 MPa (15.2 ksi) for MB1-O — about 33% more. Tensile strength is 240 MPa (34.8 ksi) vs 225 MPa (32.6 ksi).
Which condition does FabDigit quote by default, O or R?
O is the default MB1 condition in the FabDigit quote flow. The other condition is available on request or by drawing note — specify it in the material field or the part notes and the quote is priced for it.
When should I choose MB1-O over MB1-R?
Pick MB1-O when the part is bent, formed or impact-loaded. Pick MB1-R when strength drives the design.
Ready to make it?
Upload a CAD file and FabDigit prices the part in MB1-O and MB1-R side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.
Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.