Deep drawing
O-temper 1xxx sheet stretches easily, but embossing reduces the effective elongation. Generous radii and draw beads keep the pattern even and avoid splitting at dimple tops.
Automotive thermal protection
Embossed Aluminium Heat Shield Sheet for Vehicles
Embossed aluminium heat shield sheet is thin, soft O-temper aluminium (usually 1050, 1060, 1100 or 3003) with a raised hemispherical or stucco pattern rolled into it. The bright surface reflects most radiant heat from exhausts, turbochargers and catalytic converters, while the embossing makes very thin gauges stiff enough to press into shields. Metline supplies embossed sheet and coil to heat-shield makers worldwide.
- Alloys
- 1050, 1060, 1100, 3003
- Temper
- O (annealed)
- Gauge
- About 0.2 – 1.5 mm before embossing
- Patterns
- Hemispherical, stucco, diamond
How an embossed aluminium heat shield works
Most of the heat that damages components near an exhaust system arrives as infrared radiation, not by conduction. A clean, bright aluminium surface has very low emissivity, so it reflects the large majority of that radiation and re-emits little of what it absorbs. Placed between a hot exhaust and a fuel line, floor pan or plastic part, a thin aluminium shield can cut the temperature of the protected component dramatically.
Embossing does three jobs. It stiffens foil-thin metal in every direction, so a 0.3 – 0.5 mm sheet behaves like a much thicker flat sheet and resists vibration and drumming. It breaks up the surface so the shield can be deep-drawn into complex shapes without wrinkling badly. And it creates an air gap where the shield is layered against an insulator or a second sheet, which slows conduction.
Shields are made either as a single embossed layer or as a sandwich: two embossed aluminium skins around a glass-fibre, ceramic-fibre or mineral mat, crimped at the edges. Aluminium shields are used where the shield itself stays below roughly 300 – 400 °C; closer to manifolds and turbochargers, aluminised or stainless steel is used for the hot face.
Alloys used for heat shield sheet (wt %)
All four alloys are non-heat-treatable. The 1xxx grades are commercially pure aluminium; 3003 adds about 1.2 % manganese, which raises strength and keeps it better at elevated temperature. Registered Aluminum Association limits:
| Element | 1050 | 1060 | 1100 | 3003 |
|---|---|---|---|---|
| Silicon (Si) | 0.25 max | 0.25 max | Si + Fe 0.95 max | 0.6 max |
| Iron (Fe) | 0.40 max | 0.35 max | (see Si) | 0.7 max |
| Copper (Cu) | 0.05 max | 0.05 max | 0.05 – 0.20 | 0.05 – 0.20 |
| Manganese (Mn) | 0.05 max | 0.03 max | 0.05 max | 1.0 – 1.5 |
| Zinc (Zn) | 0.05 max | 0.05 max | 0.10 max | 0.10 max |
| Aluminium (Al) | 99.50 min | 99.60 min | 99.00 min | Remainder |
Mechanical properties of O-temper heat shield sheet
Heat-shield sheet is supplied fully annealed (O temper) so it can be embossed and deep drawn. Values are the specified ranges of ASTM B209 or EN 485-2 for flat sheet before embossing; embossing work-hardens the metal slightly.
| Alloy-temper | Tensile strength | Yield strength (0.2 %) | Elongation (typical min.) |
|---|---|---|---|
| 1050A-O (EN 485-2) | 65 – 95 MPa | ≥ 20 MPa | 20 – 25 % (by gauge) |
| 1060-O (ASTM B209) | 55 – 95 MPa | ≥ 17 MPa | 15 – 25 % (by gauge) |
| 1100-O (ASTM B209) | 75 – 105 MPa | ≥ 25 MPa | 15 – 30 % (by gauge) |
| 3003-O (ASTM B209) | 95 – 130 MPa | ≥ 35 MPa | 14 – 25 % (by gauge) |
Thermal properties relevant to shielding
- Melting range
- about 640 – 660 °C (1xxx); 643 – 654 °C (3003)
- Thermal emissivity
- low on clean, bright sheet (in the order of 0.05 – 0.1); rises as the surface oxidises or becomes dirty
- Thermal conductivity
- about 190 – 230 W/m·K, which spreads hot spots across the shield
- Softening
- O temper is already annealed, so heat does not cause further strength loss below about 300 °C; creep becomes relevant above this
Some marketing material quotes radiant ratings above 1,000 °C and direct-contact ratings near 600 °C for aluminium shields. Those figures describe insulated multi-layer assemblies at a stand-off distance, not the sheet itself; aluminium melts at about 650 °C, so the shield must always be designed with an air gap from the heat source.
Sheet and coil specifications
Typical supply range
- Base thickness
- About 0.2 – 1.5 mm; 0.3 – 0.8 mm is the most common for pressed shields
- Embossed thickness
- Overall height after embossing, commonly 2 – 4 times the base gauge depending on pattern
- Form
- Embossed coil for progressive or transfer presses, or cut sheets
- Width and length
- Slit and cut to blank size on request
- Patterns
- Hemispherical (spherical dimple), stucco (orange-peel), diamond and custom rolls
- Standards
- ASTM B209, EN 485 and EN 573-3; JIS H4000 for Japanese drawings
Ask for a sample panel when changing pattern or supplier: the same nominal gauge can press very differently if the emboss height or depth of the dimples changes.
Pressing, crimping and assembly
Edge crimping
Multi-layer shields are closed by folding or hemming the edges of the skins. Soft 1050 / 1060 folds tightly without cracking.
Fastening
Shields are bolted, clipped or riveted, often with steel grommets or spacers to keep the air gap and isolate vibration.
Galvanic contact
Use coated fasteners or isolating washers where an aluminium shield meets bare steel in a wet underbody zone.
Acoustic role
Embossed and perforated shields also absorb or damp noise; perforation patterns can be combined with embossing.
Recycling
Single-alloy shields are easy to recycle; multi-layer shields need the insulating mat separated.
Where embossed heat shields are used
- Exhaust and catalytic converter shields: under-floor tunnel and silencer shields protecting the floor pan and cabin
- Turbocharger and manifold surrounds: outer aluminium layers over a steel hot face
- Fuel tank and fuel line shields: keeping fuel below vapour-lock temperatures
- Engine bay and firewall: bulkhead and dash insulators combining heat and noise control
- Steering rack, starter and brake lines: small local shields near hot components
- EV applications: thermal barriers between battery modules, inverters and the cabin floor
- Outside automotive: generator sets, ovens, tunnel linings and industrial pipe insulation cladding
Aluminium versus aluminised steel and stainless steel shields
| Property | Embossed aluminium | Aluminised steel | Stainless steel |
|---|---|---|---|
| Density | 2.7 g/cm³ | about 7.8 g/cm³ | about 7.9 g/cm³ |
| Maximum shield temperature | about 300 – 400 °C | about 600 – 700 °C | 800 °C and above |
| Reflectivity (new) | Very high | High | Moderate |
| Formability | Excellent | Good | Fair |
| Corrosion in underbody | Good | Good (coating dependent) | Excellent |
| Relative cost | Low | Low | High |
The usual design is mixed: steel or stainless where the shield sees direct flame-side heat, aluminium for the larger, cooler outer shields where weight and formability matter.
How to order embossed heat shield sheet
- SpecifyAlloy and temper (e.g. 1100-O), base gauge, emboss pattern and height, coil width or blank size, and quantity.
- Confirm the standardASTM B209 or EN 485 / EN 573-3 for the base sheet, plus your drawing for pattern and forming requirements.
- QuoteWe confirm availability, tolerances, certification and delivery terms (EXW, FOB, CIF or DAP) for your plant or port.
- Process and inspectCoils are embossed, slit or cut, checked for gauge and pattern consistency and interleaved or wrapped to protect the reflective surface.
- Document and shipEach lot ships with an EN 10204 3.1 mill test certificate, heat or lot traceability and a packing list, in seaworthy export packing. Third-party inspection can be arranged on request.
References and standards
- ASTM B209 – Aluminum and Aluminum-Alloy Sheet and Plate
- EN 485-2 – Sheet, strip and plate: mechanical properties
- EN 573-3 – Aluminium and aluminium alloys: chemical composition and form of wrought products
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits (Teal Sheets)
- ASM Handbook, Vol. 2 – Properties and Selection: Nonferrous Alloys (wrought aluminium properties)
Embossed aluminium (aluminum) heat shields: frequently asked questions
Which alloy is best for an embossed heat shield?
1050, 1060 and 1100 in the O temper give the best formability for deep-drawn shields. 3003-O is about 30 % stronger and holds its strength better at temperature, so it suits larger or hotter shields.
What temperature can an aluminium heat shield withstand?
The sheet itself should stay below roughly 300 – 400 °C in service and never approach its melting range of about 650 °C. Shields work by reflecting radiant heat across an air gap; hotter positions use aluminised or stainless steel.
Why is heat shield aluminium embossed?
Embossing stiffens thin sheet in every direction, reduces vibration noise, helps deep drawing and creates air gaps in layered shields. It allows a 0.3 – 0.5 mm sheet to do the job of a much thicker flat sheet.
What thickness is used for automotive heat shields?
Most pressed shields use 0.3 – 0.8 mm base gauge before embossing; thinner foil is used for wraps and thicker gauges up to about 1.5 mm for structural shields.
Does the shield stay reflective in service?
Reflectivity falls as the surface oxidises and collects road dirt, but aluminium oxide is thin and the shield remains effective. Keeping the hot face clean and dry helps.
Can Metline supply embossed coil for progressive presses?
Yes. We supply embossed coil slit to width, or cut blanks, worldwide with mill certificates and export packing.
Making heat shields?
Send the alloy, gauge, emboss pattern and volume. Our team will confirm availability and send a delivered quotation.
