Magnesium Alloy AS41B
ASTM AS41B · UNS M10412
AS41B is a Mg-Al-Si die-casting alloy (UNS M10412) in which Mg₂Si precipitates improve elevated-temperature creep resistance relative to AZ91.
Values for the As Cast condition
AS41B tempers and conditions
AS41B is supplied in one standard condition, As Cast. As Cast is the default FabDigit quotes; the values on this page are for it.
What is AS41B?
AS41B is a Mg-Al-Si die-casting alloy (UNS M10412) in which Mg₂Si precipitates improve elevated-temperature creep resistance relative to AZ91. It is supplied as-cast for pressure die castings that see sustained heat, with 140 MPa yield, 215 MPa tensile strength, 6 % elongation, 75 HB, 68 W/m·K and service to about 175 °C. Corrosion resistance is limited (30/100) so coating and galvanic isolation are required, and weldability is low (35/100) because of die-cast porosity. AM60B is the alternative when ductility matters more than hot strength. AS41B has a density of 1.77 g/cm³ (0.0639 lb/in³), lighter than 86% of magnesium alloy grades. It melts at 565°C (1,049 °F). AS41B has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 215 MPa (31.2 ksi) — weaker than 61% of magnesium alloy grades. Elongation at break is 6% and the elastic modulus is 45 GPa (6.53 Msi).
What is AS41B used for?
- Engine crankcase and cover castings
- Gearbox housings
- Oil pan and sump castings
- Air-cooled engine housings
- Bracketry near heat sources
- Power-tool gear housings
Advantages
- High service temperature — 175°C (347 °F), better than 79% of magnesium alloy grades
Limitations
- Poor heat conductor — 68 W/m·K (39.3 BTU/hr·ft·°F), worse than 81% of magnesium alloy grades
- Difficult to weld — 35/100, worse than 80% of magnesium alloy grades
AS41B properties
Typical room-temperature values for AS41B-As Cast; bars are the position among magnesium alloy grades.
Physical3
AS41B has a density of 1.77 g/cm³ (0.0639 lb/in³), lighter than 86% of magnesium alloy grades. It melts at 565°C (1,049 °F).
Mechanical13
AS41B has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 215 MPa (31.2 ksi) — weaker than 61% of magnesium alloy grades. Elongation at break is 6% and the elastic modulus is 45 GPa (6.53 Msi).
Thermal6
AS41B is rated for continuous service to 175°C (347 °F). It conducts heat at 68 W/m·K (39.3 BTU/hr·ft·°F), worse than 81% of magnesium alloy grades. Thermal expansion is 26.1 µm/m·K (14.5 µin/in·°F).
Electrical3
AS41B conducts electricity at 13.5 % IACS, worse than 64% of magnesium alloy grades.
Chemical & Environmental3
Corrosion resistance is poor (30/100), better than 88% of magnesium alloy grades.
Sustainability4
Producing a kilogram of AS41B takes about 320 MJ of energy and emits 32 kg of CO₂ — less than 74% of magnesium alloy grades. Typical recycled content is 30%.
Manufacturability8
AS41B's machinability is excellent (95/100, better than 54% of magnesium alloy grades); weldability fair (35/100); formability not recommended (10/100).
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. AS41B is highlighted; hover a dot for its name, or open the interactive family chart.
Working with AS41B
Is AS41B easy to machine?
Cuts extremely fast with sharp, high-rake, polished-flute tools and generous chip clearance; run dry or with mineral oil — never water-based coolant — and collect fines to avoid fire risk.
Can AS41B be welded?
GTAW/GMAW with AZ61A or AZ92A filler is possible on clean material, but die-cast porosity outgasses, so joining is normally by fasteners or adhesive rather than welding.
Can AS41B be formed, bent or molded?
High-pressure die casting only; Mg₂Si raises viscosity slightly so use hotter dies and higher gate velocity than AZ91D, and expect shorter die life; no cold forming or heat treatment is applied.
Manufacturability
The process limits FabDigit's quote engine applies to AS41B. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Excellent95 / 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 |
AS41B 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 |
|---|---|---|
| Alsolid-solution and Mg17Al12 former | 3.7 – 4.8 | 4.2 |
| Siforms Mg2Si for creep resistance | 0.6 – 1.4 | 1 |
| Mniron control, corrosion | 0.35 – 0.7 | 0.45 |
| Zn | ≤ 0.12 | |
| Cuhigh-purity limit | ≤ 0.02 | |
| Nihigh-purity limit | ≤ 0 | |
| Fehigh-purity limit (Fe/Mn ratio controlled) | ≤ 0 | |
| Others (each) | ≤ 0.01 | |
| Mg | balance |
What surface finishes work on AS41B?
Deburr, alkaline clean, then chromate-free conversion coat or PEO/HAE anodic coat followed by primer + topcoat or powder coat; isolate steel fasteners with coated or Al inserts to prevent galvanic corrosion.
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 AS41B in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- M10412
- Trade names
- Creep Resistant Mg
- Also called
- AS41B-F
How much does AS41B cost?
AS41B is a standard-cost magnesium alloy ($$), cheaper than about 59% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
AS41B — frequently asked
What is AS41B used for?
AS41B is typically used for engine crankcase and cover castings, gearbox housings, oil pan and sump castings, air-cooled engine housings, bracketry near heat sources and power-tool gear housings. In short: high-temp die-cast magnesium.
What is the yield strength of AS41B?
AS41B has a typical yield strength of 140 MPa (20.3 ksi) and a tensile strength of 215 MPa (31.2 ksi) — weaker than 61% of magnesium alloy grades.
Is AS41B easy to machine?
Yes — machinability is rated excellent (95/100, better than 54% of magnesium alloy grades). Cuts extremely fast with sharp, high-rake, polished-flute tools and generous chip clearance; run dry or with mineral oil — never water-based coolant — and collect fines to avoid fire risk.
Can AS41B be welded?
With care — weldability is rated fair (35/100). GTAW/GMAW with AZ61A or AZ92A filler is possible on clean material, but die-cast porosity outgasses, so joining is normally by fasteners or adhesive rather than welding.
What surface finishes work on AS41B?
Deburr, alkaline clean, then chromate-free conversion coat or PEO/HAE anodic coat followed by primer + topcoat or powder coat; isolate steel fasteners with coated or Al inserts to prevent galvanic corrosion.
Can AS41B be formed, bent or molded?
High-pressure die casting only; Mg₂Si raises viscosity slightly so use hotter dies and higher gate velocity than AZ91D, and expect shorter die life; no cold forming or heat treatment is applied.
What is the maximum service temperature of AS41B?
AS41B is rated for continuous use to about 175°C (347 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does AS41B cost?
AS41B is a standard-cost magnesium alloy ($$), 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 AS41B?
Yes — AS41B is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B94 — Standard Specification for Magnesium-Alloy Die Castings — ASTM International (2018)
- SAE J465 / UNS M10412 alloy designation — SAE International (2016)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Specialty Handbook: Magnesium and Magnesium Alloys — ASM International (1999)
- ASM Handbook Vol. 13B — Corrosion: Materials (magnesium galvanic behaviour) — 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.