Magnesium Alloy AM100A
ASTM AM100A · UNS M10100
AM100A (UNS M10100) is a general-purpose sand and permanent-mould cast Mg-Al alloy with 10% aluminium, offering moderate strength and good castability in F, T4, T6, T61 and T7.
Reference datasheet — AM100A 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 T6 condition
AM100A tempers and conditions
AM100A is supplied in 5 conditions, soft to hard. T6 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 |
|---|---|---|---|---|---|---|
As fabricated | Lowest-cost condition for lightly loaded, dimensionally stable castings where no heat treatment is justified. | 83 | 150 | 2 | 53 HB | 68 W/m·K |
Solution heat treated and naturally aged | Pick when maximum toughness/ductility and shock resistance matter more than yield strength. | 83 | 275 | 10 | 53 HB | 66 W/m·K |
Solution heat treated and overaged (stabilized) | Choose for dimensional stability and reduced residual stress in castings that see moderate service heat or tight tolerances, trading some strength for stability. | 110 | 250 | 4 | 63 HB | — |
T6Default Solution heat treated and artificially aged | Standard supply condition: highest yield strength and hardness, accepted at the cost of very low elongation. | 152 | 275 | 1 | 69 HB | 72 W/m·K |
T6 variant, underaged | Use where the maximum hardness and compressive yield of AM100A are needed on thicker permanent-mold sections. | 160 | 275 | 1 | 74 HB | 73 W/m·K |
What is AM100A?
AM100A (UNS M10100) is a general-purpose sand and permanent-mould cast Mg-Al alloy with 10% aluminium, offering moderate strength and good castability in F, T4, T6, T61 and T7. Typical values are 152 MPa yield, 275 MPa tensile, 1% elongation, 69 HB, 72 W/m·K and machinability 96, so it suits stiffness-driven housings rather than ductile load paths. Corrosion resistance is low (score 20), service is capped at 120 °C and weldability is moderate (score 60); the alloy has largely been superseded by AZ91, which is the default substitute. AM100A has a density of 1.81 g/cm³ (0.0654 lb/in³), heavier than 58% of magnesium alloy grades. It melts at 465°C (869 °F). AM100A has a yield strength of 152 MPa (22 ksi) and a tensile strength of 275 MPa (39.9 ksi) — stronger than 62% of magnesium alloy grades. Elongation at break is 1% and the elastic modulus is 45 GPa (6.53 Msi).
What is AM100A used for?
- engine covers
- gearbox housings
- brackets
Limitations
- Limited ductility — 1%, worse than 100% of magnesium alloy grades
- Hard to polish — 45/100, worse than 93% of magnesium alloy grades
- Low fracture toughness — 12 MPa·√m (10.9 ksi·√in), worse than 92% of magnesium alloy grades
- Limited service temperature — 120°C (248 °F), worse than 78% of magnesium alloy grades
- Low electrical conductivity — 12 % IACS, worse than 78% of magnesium alloy grades
AM100A properties
Typical room-temperature values for AM100A-T6; bars are the position among magnesium alloy grades.
Physical3
AM100A has a density of 1.81 g/cm³ (0.0654 lb/in³), heavier than 58% of magnesium alloy grades. It melts at 465°C (869 °F).
Mechanical13
AM100A has a yield strength of 152 MPa (22 ksi) and a tensile strength of 275 MPa (39.9 ksi) — stronger than 62% of magnesium alloy grades. Elongation at break is 1% and the elastic modulus is 45 GPa (6.53 Msi).
Thermal6
AM100A is rated for continuous service to 120°C (248 °F). It conducts heat at 72 W/m·K (41.6 BTU/hr·ft·°F), worse than 69% of magnesium alloy grades. Thermal expansion is 25.2 µm/m·K (14 µin/in·°F).
Electrical3
AM100A conducts electricity at 12 % IACS, worse than 78% of magnesium alloy grades.
Chemical & Environmental3
Corrosion resistance is poor (20/100), worse than 77% of magnesium alloy grades.
Sustainability4
Producing a kilogram of AM100A takes about 320 MJ of energy and emits 30 kg of CO₂ — less than 74% of magnesium alloy grades. Typical recycled content is 25%.
Manufacturability8
AM100A's machinability is excellent (96/100, better than 87% of magnesium alloy grades); weldability good (60/100); formability not recommended (8/100).
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. AM100A is highlighted; hover a dot for its name, or open the interactive family chart.
Working with AM100A
Is AM100A easy to machine?
Machines faster and with lower cutting forces than any other structural metal — use sharp tools, high speed, dry or mineral-oil cutting fluid (never water-based), and keep fine chips/dust collected wet or inert to avoid fire.
Can AM100A be welded?
GTAW/GMAW with AZ92A or AZ101A filler works well in the F condition; preheat thick sections, avoid mixing with steel spatter, and re-solution/re-age after welding T6 parts to restore properties.
Can AM100A be formed, bent or molded?
A casting alloy only — good sand and permanent-mold fluidity with SF6-free cover-gas or flux melting; not cold formable, so shape must come from the mold.
AM100A 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/ageing element (Mg17Al12) | 9.3 – 10.7 | 10 |
| Mn0.10 % min; controls Fe for corrosion | 0.1 – 0.35 | 0.15 |
| Zn | ≤ 0.3 | 0.1 |
| Si | ≤ 0.3 | |
| Cuimpurity limit | ≤ 0.1 | |
| Niimpurity limit | ≤ 0.01 | |
| Fetypical high-purity practice limit; older specs control Fe via Fe/Mn ratio | ≤ 0.01 | |
| Other (each/total)others total | ≤ 0.3 | |
| Mg | balance |
What surface finishes work on AM100A?
Always clean/pickle then apply a chromate or chrome-free conversion coat, Dow 17/HAE anodize or PEO before primer and paint; isolate all steel, brass and aluminium fasteners to prevent galvanic attack.
Equivalent designations
Standards and trade names that resolve to Magnesium Alloy AM100A in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- M10100
- Also called
- AM100A-F
How much does AM100A cost?
AM100A is a standard-cost magnesium alloy ($$), cheaper than about 71% 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.
AM100A — frequently asked
What is AM100A used for?
AM100A is typically used for engine covers, gearbox housings and brackets. In short: superseded by AZ91; very low cast ductility; excellent machinability, poor corrosion.
What is the yield strength of AM100A?
AM100A has a typical yield strength of 152 MPa (22 ksi) and a tensile strength of 275 MPa (39.9 ksi) — stronger than 62% of magnesium alloy grades. Strength varies by condition: see the 5 listed tempers.
Is AM100A easy to machine?
Yes — machinability is rated excellent (96/100, better than 87% of magnesium alloy grades). Machines faster and with lower cutting forces than any other structural metal — use sharp tools, high speed, dry or mineral-oil cutting fluid (never water-based), and keep fine chips/dust collected wet or inert to avoid fire.
Can AM100A be welded?
Yes — weldability is rated good (60/100). GTAW/GMAW with AZ92A or AZ101A filler works well in the F condition; preheat thick sections, avoid mixing with steel spatter, and re-solution/re-age after welding T6 parts to restore properties.
What surface finishes work on AM100A?
Always clean/pickle then apply a chromate or chrome-free conversion coat, Dow 17/HAE anodize or PEO before primer and paint; isolate all steel, brass and aluminium fasteners to prevent galvanic attack.
Can AM100A be formed, bent or molded?
A casting alloy only — good sand and permanent-mold fluidity with SF6-free cover-gas or flux melting; not cold formable, so shape must come from the mold.
What is the maximum service temperature of AM100A?
AM100A is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between AM100A-T6 and AM100A-F?
T6 is the default condition — standard supply condition: highest yield strength and hardness, accepted at the cost of very low elongation. F: lowest-cost condition for lightly loaded, dimensionally stable castings where no heat treatment is justified. Yield strength is 152 MPa in T6 versus 83 MPa in F.
How much does AM100A cost?
AM100A is a standard-cost magnesium alloy ($$), cheaper than about 71% 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
- ASTM B199 — Magnesium-Alloy Permanent Mold Castings — ASTM International (2019)
- ASTM B80 — Magnesium-Alloy Sand Castings — ASTM International (2015)
- ASTM B93/B93M — Magnesium Alloys in Ingot Form for Sand, Permanent Mold and Die Castings — ASTM International (2020)
- ASM Specialty Handbook: Magnesium and Magnesium Alloys — ASM International (1999)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- SAE AMS 4455 / UNS M10100 designation records — SAE International (2018)
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.