Deep drawing
High n-value and good uniform elongation allow deep, complex inners. Use EDT texture or prelube for consistent friction; aluminium needs larger draw radii than steel.
Automotive inner-panel sheet
5182-O Aluminium Sheet for Automotive Body Panels
5182-O is a 4.5 % magnesium aluminium alloy in the annealed condition, and the most widely used aluminium sheet for deep-drawn car-body inner panels. It combines high strength for a non-heat-treatable alloy with excellent drawability, which suits door, bonnet and tailgate inners and complex structural pressings. Metline supplies 5182-O sheet and coil to GB/T 33227, EN 485 and OEM specifications worldwide.
- Alloy
- 5182 (Al-4.5Mg-0.35Mn)
- Temper
- O (annealed)
- Thickness
- 0.7 – 3.5 mm
- Strength
- Rm ≥ 255 MPa, A50 ≥ 23 %
Why 5182-O is the standard inner-panel alloy
An aluminium car body usually combines two sheet families. Outer panels (bonnet, doors, roof, wings) use 6xxx alloys such as 6016 or 6014, which harden in the paint oven and give dent resistance. Inner panels and structural pressings use 5xxx alloys, which do not harden in the oven but can be drawn into far deeper and more complex shapes. 5182-O is the strongest and most formable of these inner-panel alloys.
Its 4.0 – 5.0 % magnesium gives a high work-hardening rate, so the sheet strengthens as it is stretched and spreads strain evenly across the part instead of necking early. That is exactly what deep inner panels need: a door inner may have a draw depth of well over 100 mm with tight corners and many embossed features. 5182 is also the alloy used for beverage-can ends, which shows how well it tolerates severe forming.
The trade-offs are well understood. 5182 forms Lüders bands (stretcher-strain marks) during forming, so it is used where surfaces are hidden. It also must not be used for parts that sit for long periods above about 65 °C, because high-magnesium alloys then become sensitised to intergranular corrosion. Within those limits it is the most efficient sheet for inner structures.
5182 chemical composition (wt %)
Limits follow the Aluminum Association registration and EN 573-3 (EN AW-5182), as adopted in GB/T 3190.
| Element | Minimum | Maximum | Role in the alloy |
|---|---|---|---|
| Silicon (Si) | — | 0.20 | Impurity; kept low for formability |
| Iron (Fe) | — | 0.35 | Impurity; limited for ductility |
| Copper (Cu) | — | 0.15 | |
| Manganese (Mn) | 0.20 | 0.50 | Grain control and strength |
| Magnesium (Mg) | 4.0 | 5.0 | Main strengthening element; high work hardening |
| Chromium (Cr) | — | 0.10 | |
| Zinc (Zn) | — | 0.25 | |
| Titanium (Ti) | — | 0.10 | Grain refiner |
| Others, each / total | — | 0.05 / 0.15 | |
| Aluminium (Al) | Remainder | About 93.2 – 95.8 % |
Mechanical properties of 5182-O body sheet
Automotive specifications usually set both a minimum and a maximum for yield strength, because too high a yield increases springback and too low a yield reduces dent and buckling resistance of the finished part.
| Property | Automotive 5182-O (0.7 – 1.5 mm) | EN 485-2 general sheet | Typical result |
|---|---|---|---|
| Tensile strength Rm | ≥ 250 – 255 MPa | 255 – 315 MPa | about 275 MPa |
| Yield strength Rp0.2 | 110 – 150 MPa | ≥ 110 MPa | about 130 MPa |
| Elongation A50 | ≥ 23 % | band by thickness | about 25 – 27 % |
| Work-hardening exponent n | often specified, about 0.30 or higher | — | about 0.30 – 0.33 |
| Plastic strain ratio r | often specified | — | about 0.6 – 0.8 |
OEM specifications differ; the certificate reports the properties required by your specification, and forming-limit curves can be supplied on request.
Physical properties (approximate)
- Density
- 2.65 g/cm³
- Melting range
- about 577 – 638 °C
- Thermal conductivity
- about 125 – 130 W/m·K
- Electrical conductivity
- about 28 – 31 % IACS
- Coefficient of thermal expansion
- about 24 µm/m·°C (20 – 100 °C)
- Modulus of elasticity
- about 70 GPa
5182-O sizes, coils and surfaces
Typical supply range for 5182-O automotive sheet
- Tempers
- O (fully recrystallised); H111 on request
- Thickness
- 0.7 – 3.5 mm; 0.7 – 1.5 mm most common for panels
- Width
- About 800 – 2,400 mm for full-width panel stock; slit strip down to narrow widths for brackets and small pressings
- Form
- Cut sheets, blanks and coils (inner diameter 405, 505 or 605 mm)
- Surface texture
- Mill finish (MF) or electro-discharge textured (EDT) for better lubricant retention and paint appearance
- Pre-treatment
- Untreated, or titanium/zirconium conversion coating to improve adhesive bonding and paint adhesion
- Lubrication
- Dry, electrostatic oil (EO) or dry-film lubricant (prelube/hot-melt), with the coating weight agreed per order
- Order standards
- GB/T 33227, ASTM B209, EN 485 or JIS H4000, plus the customer's material specification
Widths, coil weights and surface combinations are confirmed against your press-line and blanking requirements at quotation.
5182 weighs about 2.65 kg per square metre for each millimetre of thickness:
| Thickness (mm) | kg per m² | 1250 × 2500 mm (kg) | 1500 × 3000 mm (kg) |
|---|---|---|---|
| 0.5 | 1.32 | 4.1 | 6.0 |
| 0.7 | 1.85 | 5.8 | 8.3 |
| 0.8 | 2.12 | 6.6 | 9.5 |
| 1 | 2.65 | 8.3 | 11.9 |
| 1.2 | 3.18 | 9.9 | 14.3 |
| 1.5 | 3.97 | 12.4 | 17.9 |
| 2 | 5.30 | 16.6 | 23.8 |
| 2.5 | 6.62 | 20.7 | 29.8 |
| 3 | 7.95 | 24.8 | 35.8 |
Forming and surface requirements
A body sheet is judged on more than tensile strength. Automotive sheet standards such as GB/T 33227 and the OEM material specifications that sit above them add forming, surface and processing requirements. The table summarises the points that are usually written into the purchase order.
| Requirement | What it controls | How it is specified |
|---|---|---|
| Hemming / flanging grade | Whether the edge can be folded flat (hemmed) around an inner panel without cracking | Grade agreed on the order; checked with flat-hem or bend tests |
| Paint-brush lines | Fine streaks that become visible after painting on outer panels | Grade agreed on the order for exposed parts |
| Forming limit (FLD) | The strain combinations the sheet can survive before necking | Forming limit curve supplied when the buyer requests it |
| Dent resistance | Resistance of finished panels to local denting | Test data supplied on request |
| High-strain-rate tensile data | Behaviour in crash simulation | Supplied on request for crash-relevant parts |
| Oil amount | Lubricant weight for pressing and corrosion protection in transit | g/m² per side, agreed on the order |
| Passivation / conversion film | Bonding and paint adhesion | Coating type and weight agreed on the order |
| Appearance | Scratches, roll marks, colour variation | Stricter for outer panels; minor marks that do not affect forming are acceptable on inner and structural parts |
Thickness, width and flatness tolerances
The body-panel thickness tolerances commonly applied to 0.7 – 1.5 mm automotive sheet are tighter than general-engineering tables, because thickness variation changes draw-die clearance and springback. Typical values:
| Thickness (mm) | Width 800 – 1,600 mm | Width > 1,600 – 1,800 mm | Width > 1,800 – 2,400 mm |
|---|---|---|---|
| 0.70 – 1.00 | ±0.03 mm | ±0.05 mm | ±0.08 mm |
| > 1.00 – 1.20 | ±0.04 mm | ±0.06 mm | ±0.09 mm |
| > 1.20 – 1.50 | ±0.05 mm | ±0.07 mm | ±0.10 mm |
Other dimensional limits (typical)
- Width of cut sheet
- Plus-only tolerance, from about +0.3 mm on narrow strip to +3 mm on wide sheet
- Length
- About +3 mm up to 2 m long, +5 mm over 2 m
- Flatness
- Maximum wave height of about 3 – 8 mm depending on width and thickness
- Squareness
- Diagonal difference limited in proportion to sheet width
Forming, joining and design limits
Lüders bands
Type A and B stretcher-strain marks appear on formed 5182. Use it for hidden parts, or specify a pre-strained or special-processed variant if marks must be minimised.
Joining
Self-piercing riveting, clinching and structural adhesives are standard; spot welding needs controlled surface oxide. Hemming to 6xxx outers is routine.
Paint shop
5182 does not bake-harden; it may soften very slightly in the oven. Its properties are stable for design.
Warm service limit
Do not use for parts held above about 65 °C for long periods; choose 5754 or 6xxx for heat-exposed parts.
Springback
Lower modulus than steel means more springback; die compensation and controlled yield strength keep parts in tolerance.
Where 5182-O is used
- Door inners: deep-drawn inner panels hemmed to 6xxx outers
- Bonnet and boot-lid inners: complex stiffening patterns
- Tailgate and liftgate inners: large, deep pressings
- Structural pressings: floor reinforcements, wheelhouses and brackets in cool locations
- Commercial vehicles: cab inner panels and reinforcements
5182-O compared with 5754-O and 6016-T4
| Property | 5182-O | 5754-O | 6016-T4 (outer panel) |
|---|---|---|---|
| Typical tensile strength | about 275 MPa | about 220 MPa | about 230 MPa (rises after paint bake) |
| Typical yield strength | about 130 MPa | about 100 MPa | about 110 – 120 MPa, about 200 MPa after bake |
| Formability | Excellent | Very good | Good |
| Surface after forming | Lüders marks | Fewer marks | Class A surface |
| Warm service | Limit about 65 °C | Suitable | Suitable |
| Typical use | Deep inners | Inners, warm structures | Outer panels |
How to order 5182-O body sheet
- SpecifyAlloy and temper (5182-O), gauge, width, coil ID and weight or blank size, surface texture, pre-treatment, lubricant type and weight, annual volume.
- Confirm the standardGB/T 33227 or EN 485, plus the OEM material specification with n, r, yield window and forming-limit requirements.
- QuoteWe confirm availability, tolerances, certification and delivery terms (EXW, FOB, CIF or DAP) for your plant or port.
- Process and inspectCoils are slit or blanked, pre-treated and lubricated as specified, and inspected for gauge, flatness and surface.
- Document and shipEach lot ships with an EN 10204 3.1 mill test certificate, lot traceability and a packing list, in seaworthy export packing. Third-party inspection can be arranged on request.
References and standards
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits (Teal Sheets)
- GB/T 33227-2016 – Aluminium and aluminium alloy sheet and strip for automobiles
- EN 485-2 – Sheet, strip and plate: mechanical properties
- EN 573-3 – Aluminium and aluminium alloys: chemical composition and form of wrought products
- ASM Handbook Vol. 2 – Properties and Selection: Nonferrous Alloys and Special-Purpose Materials
5182-O automotive aluminium (aluminum) sheet: frequently asked questions
Why is 5182 used for inner panels and not outer panels?
It forms Lüders bands during pressing, which would show through paint on outer panels, and it does not harden in the paint oven. Outer panels use bake-hardenable 6xxx sheet.
What strength does 5182-O have?
Typically about 275 MPa tensile and 130 MPa yield, with around 25 % elongation. Automotive specifications usually require at least 250 – 255 MPa tensile and a yield window of about 110 – 150 MPa.
Can 5182 be used near the engine or exhaust?
Not for parts held above about 65 °C for long periods, because it can become sensitised to intergranular corrosion. Use 5754 or a 6xxx alloy there.
How is 5182 joined in a car body?
Mainly by self-piercing rivets, clinching and structural adhesive, with hemming to outer panels. Spot and laser welding are also used.
What surface options are available?
Mill finish or EDT texture, untreated or titanium/zirconium pre-treated, and dry, oiled or prelubed surfaces.
Do you supply 5182-O sheet internationally?
Yes. Metline ships 5182-O sheet and coil worldwide from Mumbai with EN 10204 3.1 certificates, on EXW, FOB, CIF or DAP terms.
Need 5182-O sheet for inner panels?
Send the gauge, width, surface and annual volume. We will reply with availability, certification and a delivered price.
