Aluminum 5251
AA 5251 · UNS A95251 · EN AlMg2, AW-5251 · BS N4
5251 (EN AW-5251, AlMg2Mn0,3) is a medium-strength non-heat-treatable Al–Mg wrought alloy positioned between 5005 and 5052, supplied almost exclusively as sheet, coil and tread plate.
5251 tempers and conditions
5251 is supplied in 15 conditions, soft to hard.
Compare all 15 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Pick for deep drawing, tight-radius bending, stretch forming or spinning where maximum ductility matters. | 75 | 180 | 23 | 45 HB | 35 % IACS |
As fabricated | 5251 in the as-fabricated condition — properties result from the forming process only and are not guaranteed, giving soft, highly formable Al-Mg2Mn sheet, plate or extrusion. | 75 | 175 | 20 | 45 HB | 35 % IACS |
Strain hardened from hot working only | 5251-H112 is hot-worked plate or extruded product that acquires slight strain hardening during fabrication and is supplied to guaranteed minimum strength limits. | 85 | 185 | 18 | 48 HB | 35 % IACS |
Strain hardened and partially annealed, quarter hard | The standard stocked 5251 sheet/coil temper: good balance of strength, bending and weldability for panels, tanks, vehicle bodywork and marine fittings. | 150 | 210 | 10 | 57 HB | 34 % IACS |
Strain hardened, quarter hard | Lightly cold-rolled sheet/coil where a modest strength gain is wanted with good remaining bendability; less common than the stabilised H22. | 150 | 205 | 9 | 56 HB | 34 % IACS |
Strain hardened and stabilized, quarter hard | Stabilised equivalent of H22 used where long-term property stability of the Al–Mg sheet is specified; properties are interchangeable with H22 in EN 485-2. | 150 | 210 | 10 | 57 HB | 34 % IACS |
Strain hardened and stabilized, half hard | Stabilised half-hard sheet/plate for load-bearing panels, tread plate and welded fabrications needing stable properties in service. | 180 | 230 | 8 | 65 HB | 34 % IACS |
Strain hardened and partially annealed, half hard | Choose when H22 strength is insufficient but moderate forming (brake bending to generous radii) is still required. | 180 | 230 | 8 | 65 HB | 34 % IACS |
Strain hardened, half hard | Half-hard cold-rolled sheet for flat panels and mildly formed parts needing higher stiffness under load. | 180 | 230 | 7 | 64 HB | 34 % IACS |
Strain hardened, three-quarter hard | Use where flat, springy, higher-strength thin sheet is needed and forming is limited to gentle radii. | 200 | 250 | 5 | 71 HB | 33.5 % IACS |
Strain hardened and partially annealed, three-quarter hard | Higher-strength stabilised sheet for lightly formed structural panels and roll-formed sections. | 200 | 250 | 5 | 72 HB | 34 % IACS |
Strain hardened and stabilized, three-quarter hard | Stabilised three-quarter-hard sheet for high-strength flat product with limited bending. | 200 | 250 | 5 | 72 HB | 33.5 % IACS |
Strain hardened and partially annealed, full hard | Strongest commercially supplied 5251 sheet temper; for flat, high-strength thin-gauge parts with essentially no forming. | 230 | 275 | 4 | 78 HB | 33.5 % IACS |
Strain hardened and stabilized, full hard | Stabilised full-hard thin sheet where maximum strength and dimensional stability are needed and no forming is planned. | 230 | 275 | 4 | 78 HB | 33 % IACS |
Strain hardened, full hard | Maximum cold-worked strength in thin gauges (shims, flat springs, roll-formed profiles); minimal bendability. | 235 | 275 | 4 | 78 HB | 33 % IACS |
What is 5251?
5251 (EN AW-5251, AlMg2Mn0,3) is a medium-strength non-heat-treatable Al–Mg wrought alloy positioned between 5005 and 5052, supplied almost exclusively as sheet, coil and tread plate. It is chosen for its good cold formability, excellent weldability and very good resistance to marine and industrial atmospheres, at strengths well above pure-Al or 3000-series grades. Limits are that strength can only be raised by cold work (H tempers), it softens above roughly 120–150 °C, and — like all 5000-series alloys with ≥3 % Mg it is less of a concern, but heavily worked material held warm — it can be sensitive to work-hardened surface streaking and is not free-machining. 5251 has a density of 2.69 g/cm³ (0.0972 lb/in³), lighter than 67% of aluminum grades. It melts at 607°C (1,125 °F). 5251 has a yield strength of 150 MPa (21.8 ksi) and a tensile strength of 210 MPa (30.5 ksi) — weaker than 65% of aluminum grades. Elongation at break is 10% and the elastic modulus is 70 GPa (10.2 Msi).
What is 5251 used for?
- Vehicle body sheet
- Architectural panels and cladding
- Tread plate flooring and walkways
- Welded tanks and containers
- Road tanker and trailer panels
- Marine and industrial enclosures
- Pressed and deep-drawn housings
Advantages
- Readily welded — 88/100, better than 85% of aluminum grades
- Forms and bends easily — 72/100, better than 85% of aluminum grades
- Good corrosion resistance — 72/100, better than 83% of aluminum grades
Limitations
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
5251 properties
Typical room-temperature values; bars are the position among aluminum grades.
Physical3
5251 has a density of 2.69 g/cm³ (0.0972 lb/in³), lighter than 67% of aluminum grades. It melts at 607°C (1,125 °F).
Mechanical10
5251 has a yield strength of 150 MPa (21.8 ksi) and a tensile strength of 210 MPa (30.5 ksi) — weaker than 65% of aluminum grades. Elongation at break is 10% and the elastic modulus is 70 GPa (10.2 Msi).
Thermal6
5251 is rated for continuous service to 120°C (248 °F). It conducts heat at 155 W/m·K (89.6 BTU/hr·ft·°F), better than 71% of aluminum grades. Thermal expansion is 23.8 µm/m·K (13.2 µin/in·°F).
Electrical3
5251 conducts electricity at 34 % IACS, worse than 52% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is very good (72/100), better than 83% of aluminum grades.
Sustainability4
Producing a kilogram of 5251 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 30%.
Manufacturability7
5251's machinability is fair (45/100, worse than 72% of aluminum grades); weldability excellent (88/100); formability very good (72/100).
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 aluminum family
Yield strength against density for every aluminum grade FabDigit runs. 5251 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 5251
Is 5251 easy to machine?
Machinable but gummy in O/H22 — use sharp polished-flute carbide, high rake, high speed and flood lubrication to avoid built-up edge; harder H2x/H3x tempers chip better.
Can 5251 be welded?
Excellent for GTAW/GMAW and resistance welding with 5356 or 5183 filler; weld metal returns to about O-temper strength, so design joints on annealed properties.
Can 5251 be formed, bent or molded?
Very good cold formability — deep draw and spin in O, brake-bend H22/H24 with generous radii and allow for springback; avoid warm working above ~150 °C which softens H tempers.
Manufacturability
The process limits FabDigit applies to 5251. Every 5251 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better45 / 100 |
|---|---|
| ISO material group | N.1 |
| Cutting speed (rough / finish) | 350 / 420 m/min |
| Minimum wall | 0.5 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 8× diameter |
| Best surface (machined / polished) | Ra 0.8 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Excellent72 / 100 |
|---|---|
| Weldability | Better88 / 100 |
| Bendable | Yes |
5251 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 |
|---|---|---|
| SiEN 573-3 | ≤ 0.4 | 0.15 |
| Fe | ≤ 0.5 | 0.25 |
| Cu | ≤ 0.15 | 0.03 |
| Mn | 0.1 – 0.5 | 0.3 |
| Mgprincipal strengthening element | 1.7 – 2.4 | 2 |
| Cr | ≤ 0.15 | 0.05 |
| Zn | ≤ 0.15 | 0.05 |
| Ti | ≤ 0.15 | 0.03 |
| Others (each)total 0.15 max | ≤ 0.05 | |
| Al | balance |
What surface finishes work on 5251?
Anodises brightly (clear, hard or colour) and takes chromate/pretreated paint and powder coat well; mechanical polishing is fair, so brushed or embossed finishes are common.
Surface treatments FabDigit runs on aluminum 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).
Passivation
Conversion Coating
PVD Coating
Equivalent designations
Standards and trade names that resolve to Aluminum 5251 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- A95251
- EN / DIN / Werkstoff-Nr.
- AlMg2AW-52513.3525AlMg2Mn0,3AlMg2Mn0.3
- BS
- N4
How much does 5251 cost?
5251 is a budget-cost aluminum ($), cheaper than about 83% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
5251 — frequently asked
What is 5251 used for?
5251 is typically used for vehicle body sheet, architectural panels and cladding, tread plate flooring and walkways, welded tanks and containers, road tanker and trailer panels and marine and industrial enclosures. In short: european 5251 sheet alloy.
What is the yield strength of 5251?
5251 has a typical yield strength of 150 MPa (21.8 ksi) and a tensile strength of 210 MPa (30.5 ksi) — weaker than 65% of aluminum grades. Strength varies by condition: see the 15 listed tempers.
Is 5251 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 72% of aluminum grades). Machinable but gummy in O/H22 — use sharp polished-flute carbide, high rake, high speed and flood lubrication to avoid built-up edge; harder H2x/H3x tempers chip better.
Can 5251 be welded?
Yes — weldability is rated excellent (88/100). Excellent for GTAW/GMAW and resistance welding with 5356 or 5183 filler; weld metal returns to about O-temper strength, so design joints on annealed properties.
What surface finishes work on 5251?
Anodises brightly (clear, hard or colour) and takes chromate/pretreated paint and powder coat well; mechanical polishing is fair, so brushed or embossed finishes are common.
Can 5251 be formed, bent or molded?
Very good cold formability — deep draw and spin in O, brake-bend H22/H24 with generous radii and allow for springback; avoid warm working above ~150 °C which softens H tempers.
What is the maximum service temperature of 5251?
5251 is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 5251 cost?
5251 is a budget-cost aluminum ($), cheaper than about 83% 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 5251?
Yes — 5251 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- EN 573-3 Aluminium and aluminium alloys — chemical composition of wrought products — CEN (2019)
- EN 485-2 Aluminium and aluminium alloys — sheet, strip and plate: mechanical properties — CEN (2016)
- 5251 Aluminium alloy sheet data — Aalco Metals (2023)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol.13 — Corrosion — 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.