Magnesium Alloy AS41
ASTM AS41 · EN MC21320, MgAl4Si
AS41 is a magnesium–aluminium–silicon high-pressure die-casting alloy (MgAl4Si, AS41A/AS41B, MC21320) in which the silicon addition improves creep resistance relative to AZ91D and AM60.
Reference datasheet — AS41 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 F condition
AS41 tempers and conditions
AS41 is supplied in 3 conditions, soft to hard. F 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 |
|---|---|---|---|---|---|---|
FDefault As fabricated | Use the standard as-die-cast state, with no heat treatment after high-pressure die casting, for housings in normal warm service to 150 °C at 140 MPa yield and 240 MPa tensile. | 140 | 240 | 6 | 60 HB | 68 W/m·K |
Commercial-purity composition, as die cast | Use the older commercial-purity composition, with wider Fe/Ni/Cu limits, only in non-corrosive environments: mechanical properties match the high-purity version but salt-spray corrosion is ten times faster. | 140 | 240 | 6 | 60 HB | 14 % IACS |
High-purity (low Fe/Ni/Cu) composition, as die cast | Choose the current high-purity composition (Fe ≤ 0.0035%, Ni ≤ 0.001%, Cu ≤ 0.015%) for automotive die castings; salt-spray rate approaches high-purity AZ91D at the same 140 MPa yield. | 140 | 240 | 6 | 60 HB | 14 % IACS |
Supply forms, finishes and certifications
Ways AS41 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
Ingot | Remelt die-casting ingot supply condition | Supply form |
What is AS41?
AS41 is a magnesium–aluminium–silicon high-pressure die-casting alloy (MgAl4Si, AS41A/AS41B, MC21320) in which the silicon addition improves creep resistance relative to AZ91D and AM60. It is used for die-cast powertrain housings that run warm, giving 140 MPa yield, 240 MPa tensile, 6% elongation and 60 HB in the as-cast F condition, thermal conductivity of 68 W/m·K and service to about 150 °C. Bare corrosion resistance is low, so conversion coating and paint are mandatory, and die-cast porosity limits fusion welding. AM60 is the nearest alternative where ductility matters more than creep strength. AS41 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). AS41 has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 240 MPa (34.8 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 AS41 used for?
- engine blocks
- transmission cases
- crankcases
- powertrain brackets
Limitations
- Difficult to weld — 30/100, worse than 90% of magnesium alloy grades
- Poor heat conductor — 68 W/m·K (39.3 BTU/hr·ft·°F), worse than 81% of magnesium alloy grades
AS41 properties
Typical room-temperature values for AS41-F; bars are the position among magnesium alloy grades.
Physical3
AS41 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).
Mechanical14
AS41 has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 61% of magnesium alloy grades. Elongation at break is 6% and the elastic modulus is 45 GPa (6.53 Msi).
Thermal6
AS41 is rated for continuous service to 150°C (302 °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
AS41 conducts electricity at 14 % IACS, worse than 58% of magnesium alloy grades.
Chemical & Environmental3
Corrosion resistance is poor (30/100), better than 88% of magnesium alloy grades.
Sustainability4
Producing a kilogram of AS41 takes about 320 MJ of energy and emits 30 kg of CO₂ — less than 74% of magnesium alloy grades. Typical recycled content is 35%.
Manufacturability8
AS41's machinability is excellent (95/100, better than 54% of magnesium alloy grades); weldability poor (30/100); 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. AS41 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with AS41
Is AS41 easy to machine?
Machinability is excellent: run high spindle speeds and heavy feeds with sharp, positive-rake tooling. Use ample mineral-oil cutting fluid or cut dry with fire precautions, because fine chips and dust are flammable; do not let chips accumulate in water-based emulsions.
Can AS41 be welded?
Die castings contain gas porosity, so fusion welding tends to produce pores and cracks. Small areas can be repair-welded locally by TIG or laser with AZ61 or AZ92 filler; for structural joints prefer self-pierce riveting, threaded inserts or adhesive bonding.
Can AS41 be formed, bent or molded?
Hot- or cold-chamber high-pressure die casting, with pouring temperature about 650–690 °C and die temperature 200–260 °C. The silicon content makes fluidity slightly lower than AZ91D, so raise gate velocity and die temperature for walls below 1.5 mm.
AS41 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 |
|---|---|---|
| AlAS41A: 3.5–5.0 | 3.7 – 4.8 | 4.2 |
| Siforms Mg2Si for creep resistance | 0.6 – 1.4 | 1 |
| MnFe control / corrosion | 0.35 – 0.6 | 0.4 |
| Zn | ≤ 0.1 | 0.05 |
| CuAS41A: 0.04 max | ≤ 0.02 | |
| NiAS41A: 0.01 max | ≤ 0 | |
| Fehigh-purity limit, Fe/Mn ratio controlled | ≤ 0 | |
| Others (each) | ≤ 0.02 | |
| Mg | balance |
What surface finishes work on AS41?
Conventional sulphuric-acid anodizing is not applicable; use chromate or chrome-free conversion coatings, Dow 17 or HAE anodic treatment, or micro-arc oxidation, then epoxy primer and topcoat. Insulate fastener locations with isolating washers to prevent galvanic corrosion.
Equivalent designations
Standards and trade names that resolve to Magnesium Alloy AS41 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- AS41B
- EN / DIN / Werkstoff-Nr.
- MC21320MgAl4Si
How much does AS41 cost?
AS41 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.
AS41 — frequently asked
What is AS41 used for?
AS41 is typically used for engine blocks, transmission cases, crankcases and powertrain brackets. In short: creep-resistant die-cast magnesium; warm-running powertrain grade; machines faster than aluminium.
What is the yield strength of AS41?
AS41 has a typical yield strength of 140 MPa (20.3 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 61% of magnesium alloy grades. Strength varies by condition: see the 3 listed tempers.
Is AS41 easy to machine?
Yes — machinability is rated excellent (95/100, better than 54% of magnesium alloy grades). Machinability is excellent: run high spindle speeds and heavy feeds with sharp, positive-rake tooling. Use ample mineral-oil cutting fluid or cut dry with fire precautions, because fine chips and dust are flammable; do not let chips accumulate in water-based emulsions.
Can AS41 be welded?
Not readily — weldability is rated poor (30/100). Die castings contain gas porosity, so fusion welding tends to produce pores and cracks. Small areas can be repair-welded locally by TIG or laser with AZ61 or AZ92 filler; for structural joints prefer self-pierce riveting, threaded inserts or adhesive bonding.
What surface finishes work on AS41?
Conventional sulphuric-acid anodizing is not applicable; use chromate or chrome-free conversion coatings, Dow 17 or HAE anodic treatment, or micro-arc oxidation, then epoxy primer and topcoat. Insulate fastener locations with isolating washers to prevent galvanic corrosion.
Can AS41 be formed, bent or molded?
Hot- or cold-chamber high-pressure die casting, with pouring temperature about 650–690 °C and die temperature 200–260 °C. The silicon content makes fluidity slightly lower than AZ91D, so raise gate velocity and die temperature for walls below 1.5 mm.
What is the maximum service temperature of AS41?
AS41 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 AS41-F and AS41A-F?
F is the default condition — use the standard as-die-cast state, with no heat treatment after high-pressure die casting, for housings in normal warm service to 150 °C at 140 MPa yield and 240 MPa tensile. AS41A-F: use the older commercial-purity composition, with wider Fe/Ni/Cu limits, only in non-corrosive environments: mechanical properties match the high-purity version but salt-spray corrosion is ten times faster. Yield strength is 140 MPa in F versus 140 MPa in AS41A-F.
How much does AS41 cost?
AS41 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 B94 — Standard Specification for Magnesium-Alloy Die Castings — ASTM International (2018)
- 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)
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.