Magnesium Alloy MA8-HR (Hot rolled)
Supply condition
Thicker plate delivered as hot-rolled; balanced strength and ductility for machined structural parts.
Values for the HR condition
Other MA8 tempers and conditions
MA8 is listed in 6 conditions; see the grade overview at MA8.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As-welded deposit | Design value for TIG/MIG butt joints in annealed MA8 sheet — near-parent strength, which is why this grade is chosen for welded tanks and skins. | 120 | 230 | 8 | 42 HB | 33 % IACS |
MDefault Thermomechanically controlled processed | Standard stocked condition for MA8 sheet: softest, most formable and most weldable, use where forming or welding follows. | 130 | 240 | 15 | 45 HB | — |
HRThis page Hot rolled | Thicker plate delivered as hot-rolled; balanced strength and ductility for machined structural parts. | 140 | 235 | 12 | 48 HB | 34 % IACS |
Forged | Hot die-forged parts (300–400 °C); use when a shaped part must combine moderate strength with good weld repairability. | 150 | 240 | 12 | 47 HB | 34 % IACS |
F | As-extruded bars and sections; slightly higher yield than annealed sheet due to worked texture, main form for machined brackets. | 165 | 250 | 12 | 48 HB | 34 % IACS |
Hardened | Choose for flat panels needing higher yield strength and stiffness-per-thickness where no severe forming or post-weld strength is required. | 200 | 265 | 8 | 55 HB | — |
What is MA8-HR?
MA8-HR is MA8 supplied in the HR condition — thicker plate delivered as hot-rolled; balanced strength and ductility for machined structural parts. MA8-HR has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 235 MPa (34.1 ksi) — weaker than 61% of magnesium alloy grades. Elongation at break is 12% and the elastic modulus is 43 GPa (6.24 Msi). MA8-HR has a density of 1.78 g/cm³ (0.0643 lb/in³), lighter than 78% of magnesium alloy grades. It melts at 648°C (1,198 °F). M is the default condition FabDigit quotes; HR is available on request or by drawing note.
Advantages
- High electrical conductivity — 34 % IACS, better than 100% of magnesium alloy grades
- Conducts heat well — 138 W/m·K (79.7 BTU/hr·ft·°F), better than 98% of magnesium alloy grades
- Readily welded — 88/100, better than 96% of magnesium alloy grades
- Tough — resists crack growth — 16 MPa·√m (14.6 ksi·√in), better than 87% of magnesium alloy grades
- Forms and bends easily — 32/100, better than 85% of magnesium alloy grades
MA8-HR properties
Typical room-temperature values for MA8-HR; 21 are specific to this condition. Other listed values are MA8 reference data and may not represent this condition. Bars are the position among magnesium alloy grades.
Physical3
MA8-HR has a density of 1.78 g/cm³ (0.0643 lb/in³), lighter than 78% of magnesium alloy grades. It melts at 648°C (1,198 °F).
Mechanical13
MA8-HR has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 235 MPa (34.1 ksi) — weaker than 61% of magnesium alloy grades. Elongation at break is 12% and the elastic modulus is 43 GPa (6.24 Msi).
Thermal6
MA8-HR is rated for continuous service to 150°C (302 °F). It conducts heat at 138 W/m·K (79.7 BTU/hr·ft·°F), better than 98% of magnesium alloy grades. Thermal expansion is 26 µm/m·K (14.4 µin/in·°F).
Electrical3
MA8-HR conducts electricity at 34 % IACS, better than 100% of magnesium alloy grades.
Chemical & Environmental3
Corrosion resistance is poor (28/100), better than 78% of magnesium alloy grades.
Sustainability4
Producing a kilogram of MA8-HR takes about 330 MJ of energy and emits 30 kg of CO₂ — less than 56% of magnesium alloy grades. Typical recycled content is 25%.
Manufacturability7
MA8-HR's machinability is excellent (95/100, better than 54% of magnesium alloy grades); weldability excellent (88/100); formability poor (32/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with MA8-HR
Is MA8 easy to machine?
Machines faster and with lower cutting forces than any aluminium — use sharp, high-rake tools, high speed, no water-based coolant on fine chips, and keep swarf wet/contained because Mg fines are a fire hazard.
Can MA8 be welded?
Best-in-class among wrought Mg alloys: AC-TIG or MIG with matching Mg-Mn filler in argon, no post-weld heat treatment needed for the annealed condition; keep interpass clean and avoid moisture porosity.
Can MA8 be formed, bent or molded?
Cold formability is limited by the HCP structure — bend radii ≥5t cold; form, deep-draw or stretch at 250–350 °C where elongation exceeds 40 %; stress-relieve cold-worked parts at ~260 °C.
What surface finishes work on MA8?
Do not use aluminium sulphuric anodizing; specify chromate-free conversion coating, HAE/Dow 17 anodize or PEO, then epoxy primer + topcoat, and insulate all steel/copper fasteners to avoid galvanic attack.
MA8 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 |
|---|---|---|
| Mnprimary solid-solution / corrosion-improving addition | 1.5 – 2.5 | 2 |
| Cegrain refinement, hot-forming ductility | 0.15 – 0.35 | 0.25 |
| Alimpurity limit | ≤ 0.3 | — |
| Znimpurity limit | ≤ 0.3 | — |
| Siimpurity limit | ≤ 0.1 | — |
| Feimpurity; must stay low for corrosion | ≤ 0.05 | — |
| Cuimpurity limit | ≤ 0.05 | — |
| Niimpurity; strongly harmful to corrosion | ≤ 0.01 | — |
| Beoptional melt-protection addition | ≤ 0.02 | — |
| Mg | balance | — |
MA8-HR — frequently asked
What is MA8-HR used for?
MA8-HR is typically used for welded fuel tanks, sheet structures and aircraft skin panels. In short: most weldable wrought magnesium; aluminium-free Mg-Mn sheet; moderate strength only.
What is the yield strength of MA8-HR?
MA8-HR has a typical yield strength of 140 MPa (20.3 ksi) and a tensile strength of 235 MPa (34.1 ksi) — weaker than 61% of magnesium alloy grades. Strength varies by condition: see the 6 listed tempers.
Is MA8-HR easy to machine?
Yes — machinability is rated excellent (95/100, better than 54% of magnesium alloy grades). Machines faster and with lower cutting forces than any aluminium — use sharp, high-rake tools, high speed, no water-based coolant on fine chips, and keep swarf wet/contained because Mg fines are a fire hazard.
Can MA8-HR be welded?
Yes — weldability is rated excellent (88/100). Best-in-class among wrought Mg alloys: AC-TIG or MIG with matching Mg-Mn filler in argon, no post-weld heat treatment needed for the annealed condition; keep interpass clean and avoid moisture porosity.
What surface finishes work on MA8-HR?
Do not use aluminium sulphuric anodizing; specify chromate-free conversion coating, HAE/Dow 17 anodize or PEO, then epoxy primer + topcoat, and insulate all steel/copper fasteners to avoid galvanic attack.
Can MA8-HR be formed, bent or molded?
Cold formability is limited by the HCP structure — bend radii ≥5t cold; form, deep-draw or stretch at 250–350 °C where elongation exceeds 40 %; stress-relieve cold-worked parts at ~260 °C.
What is the maximum service temperature of MA8-HR?
MA8-HR is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between MA8-M and MA8-H?
M is the default condition — standard stocked condition for MA8 sheet: softest, most formable and most weldable, use where forming or welding follows. H: choose for flat panels needing higher yield strength and stiffness-per-thickness where no severe forming or post-weld strength is required. Yield strength is 130 MPa in M versus 200 MPa in H.
Sources
- ГОСТ 14957-76 Сплавы магниевые деформируемые. Марки — Gosstandart (1976)
- ГОСТ 22635-77 Листы из магниевых сплавов — Gosstandart (1977)
- ASM Specialty Handbook: Magnesium and Magnesium Alloys (M1A data) — ASM International (1999)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- Марочник сталей и сплавов — МА8 — Mashinostroenie (2003)
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.