Magnesium Alloy M1A
UNS M15100 · ASTM B107 · EN 3.5200 · ISO MgMn2
M1A is a basic Mg-Mn wrought alloy (UNS M15100, 3.5200) supplied as sheet, plate and extrusions in O, F and H24, with manganese rather than aluminium as the main addition.
Values for the O condition
M1A tempers and conditions
M1A is supplied in 3 conditions, soft to hard. O is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefault Annealed | Softest, most formable condition — pick for deep forming, bending and welded fabrications from sheet. | 115 | 230 | 12 | 44 HB | — |
As fabricated | Standard condition for ASTM B107 extrusions and B91 forgings — best strength/ductility combination available in M1A. | 179 | 255 | 12 | 44 HB | — |
Strain hardened and partially annealed, half hard | Hard-rolled sheet for flat panels and skins where higher yield strength matters more than bend radius. | 180 | 255 | 6 | 50 HB | — |
What is M1A?
M1A is a basic Mg-Mn wrought alloy (UNS M15100, 3.5200) supplied as sheet, plate and extrusions in O, F and H24, with manganese rather than aluminium as the main addition. It is specified for corrosion resistance and weldability rather than strength, offering 115 MPa yield, 230 MPa tensile strength, 12% elongation, 44 HB and service to 150 °C. Because Mg-Mn is not susceptible to stress-corrosion cracking, welded assemblies usually need no post-weld stress relief. Strength is well below AZ31B, which is the usual substitute when load capacity matters. M1A has a density of 1.76 g/cm³ (0.0636 lb/in³), lighter than 94% of magnesium alloy grades. It melts at 648°C (1,198 °F). M1A has a yield strength of 115 MPa (16.7 ksi) and a tensile strength of 230 MPa (33.4 ksi) — weaker than 80% of magnesium alloy grades. Elongation at break is 12% and the elastic modulus is 45 GPa (6.53 Msi).
What is M1A used for?
- Sacrificial anodes for water heaters and tanks
- Automotive trim and covers
- Welded magnesium sheet assemblies
- Corrosion-exposed marine hardware
- Formed housings and panels
- Extruded low-stress profiles
- Cathodic protection strips
Advantages
- Conducts heat well — 138 W/m·K (79.7 BTU/hr·ft·°F), better than 98% of magnesium alloy grades
- Forms and bends easily — 55/100, better than 98% of magnesium alloy grades
- High electrical conductivity — 33 % IACS, better than 97% of magnesium alloy grades
- Readily welded — 88/100, better than 96% of magnesium alloy grades
Limitations
- Low strength — 115 MPa (16.7 ksi), worse than 80% of magnesium alloy grades
M1A properties
Typical room-temperature values for M1A-O; bars are the position among magnesium alloy grades.
Physical3
M1A has a density of 1.76 g/cm³ (0.0636 lb/in³), lighter than 94% of magnesium alloy grades. It melts at 648°C (1,198 °F).
Mechanical13
M1A has a yield strength of 115 MPa (16.7 ksi) and a tensile strength of 230 MPa (33.4 ksi) — weaker than 80% of magnesium alloy grades. Elongation at break is 12% and the elastic modulus is 45 GPa (6.53 Msi).
Thermal6
M1A 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
M1A conducts electricity at 33 % IACS, better than 97% of magnesium alloy grades.
Chemical & Environmental3
Corrosion resistance is poor (28/100), better than 78% of magnesium alloy grades.
Sustainability4
Producing a kilogram of M1A takes about 350 MJ of energy and emits 32 kg of CO₂ — more than 74% of magnesium alloy grades. Typical recycled content is 25%.
Manufacturability8
M1A's machinability is excellent (96/100, better than 87% of magnesium alloy grades); weldability excellent (88/100); formability good (55/100).
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. M1A is highlighted; hover a dot for its name, or open the interactive family chart.
Working with M1A
Is M1A easy to machine?
Cuts faster and with lower power than any other structural metal — use sharp high-rake tools, high speed, no water-based coolant, and keep fine chips/dust controlled to avoid fire.
Can M1A be welded?
Excellent GTAW/GMAW weldability with EZ33A or M1A/AZ61A filler under argon or helium; Mg-Mn is not susceptible to stress-corrosion cracking, so post-weld stress relief is usually unnecessary.
Can M1A be formed, bent or molded?
Cold formability is limited by the HCP structure — warm form at 200–350 °C for tight bends, deep draws and stretch forming; anneal 340–370 °C between passes.
Manufacturability
The process limits FabDigit's quote engine applies to M1A. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Excellent96 / 100 |
|---|---|
| ISO material group | N.7 |
| Cutting speed (rough / finish) | 400 / 460 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1.5 mm |
| Drill depth limit | 8× diameter |
| Best surface (machined / polished) | Ra 0.8 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Fair55 / 100 |
|---|---|
| Weldability | Better88 / 100 |
| Bendable | Yes |
M1A 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 |
|---|---|---|
| Mnmanganese is the only intentional addition | 1.2 – 2 | 1.5 |
| Alimpurity limit | ≤ 0.3 | |
| Ca | ≤ 0.3 | |
| Cu | ≤ 0.05 | |
| Si | ≤ 0.1 | |
| Nikept very low for corrosion resistance | ≤ 0.01 | |
| Others (each)total 0.30 max | ≤ 0.05 | |
| Mg | balance |
What surface finishes work on M1A?
Do not sulfuric-anodize; apply chromate/fluoride conversion or magnesium anodic coatings (Dow 17, HAE, Keronite) followed by epoxy primer/paint, and isolate from steel, brass and carbon fibre with sealants or non-metallic washers.
Surface treatments FabDigit runs on magnesium alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Conversion Coating
Organic Coating
Equivalent designations
Standards and trade names that resolve to Magnesium Alloy M1A in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- M15100
- ASTM
- B107
- EN / DIN / Werkstoff-Nr.
- 3.5200
- ISO
- MgMn2
How much does M1A cost?
M1A is a standard-cost magnesium alloy ($$), cheaper than about 59% 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.
M1A — frequently asked
What is M1A used for?
M1A is typically used for sacrificial anodes for water heaters and tanks, automotive trim and covers, welded magnesium sheet assemblies, corrosion-exposed marine hardware, formed housings and panels and extruded low-stress profiles. In short: weldable magnesium sheet.
What is the yield strength of M1A?
M1A has a typical yield strength of 115 MPa (16.7 ksi) and a tensile strength of 230 MPa (33.4 ksi) — weaker than 80% of magnesium alloy grades. Strength varies by condition: see the 3 listed tempers.
Is M1A easy to machine?
Yes — machinability is rated excellent (96/100, better than 87% of magnesium alloy grades). Cuts faster and with lower power than any other structural metal — use sharp high-rake tools, high speed, no water-based coolant, and keep fine chips/dust controlled to avoid fire.
Can M1A be welded?
Yes — weldability is rated excellent (88/100). Excellent GTAW/GMAW weldability with EZ33A or M1A/AZ61A filler under argon or helium; Mg-Mn is not susceptible to stress-corrosion cracking, so post-weld stress relief is usually unnecessary.
What surface finishes work on M1A?
Do not sulfuric-anodize; apply chromate/fluoride conversion or magnesium anodic coatings (Dow 17, HAE, Keronite) followed by epoxy primer/paint, and isolate from steel, brass and carbon fibre with sealants or non-metallic washers.
Can M1A be formed, bent or molded?
Cold formability is limited by the HCP structure — warm form at 200–350 °C for tight bends, deep draws and stretch forming; anneal 340–370 °C between passes.
What is the maximum service temperature of M1A?
M1A 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 M1A-O and M1A-H24?
O is the default condition — softest, most formable condition — pick for deep forming, bending and welded fabrications from sheet. H24: hard-rolled sheet for flat panels and skins where higher yield strength matters more than bend radius. Yield strength is 115 MPa in O versus 180 MPa in H24.
How much does M1A cost?
M1A is a standard-cost magnesium alloy ($$), cheaper than about 59% 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.
Can FabDigit make parts in M1A?
Yes — M1A is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B107/B107M — Magnesium-Alloy Extruded Bars, Rods, Profiles, Tubes and Wire — ASTM International (2021)
- ASTM B90/B90M — Magnesium-Alloy Sheet and Plate — ASTM International (2021)
- ASTM B91 — Magnesium-Alloy Forgings — ASTM International (2017)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (Magnesium alloys) — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion of Magnesium and Magnesium Alloys — ASM International (2005)
- ASTM D1732 / MIL-M-3171 — Magnesium conversion and anodic coatings — ASTM / US DoD (2019)
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.