1050 3003 aluminum circles for cookware and traffic signs
Aluminum circles are widely used in cookware and traffic sign manufacturing due to their excellent formability, corrosion resistance, and surface finish. Among commonly used alloys, 1050 and 3003 aluminum circles is know for different reasons: 1050 (commercially pure aluminum) for its superior corrosion resistance and conductivity, and 3003 (Al-Mn alloy) for better strength while maintaining good formability and weldability.
Aluminum circles are discs stamped or cut from aluminum coil or sheet and are used as raw blanks for deep drawing, spinning, or stamping into finished parts. Their advantages include:
- Excellent plasticity and formability for deep drawing (important for cookware).
- Good corrosion resistance and long-term durability (important for both cookware and outdoor traffic signs).
- Lightweight with favorable strength-to-weight ratio (beneficial for large signs and portable cookware).
- Uniform thickness and smooth surface finish enabling anodizing, painting, or coating.
Typical Applications
- Cookware: pots, pans, pressure cooker housings, lids, woks, and other deep-drawn kitchenware components.
- Traffic signs: reflective sign substrates, sign faces, mounting plates, and backing discs for round sign heads.
- Other: lighting reflectors, decorative discs, cookware lids, and industrial end caps.
Differences: 1050 vs 3003 Aluminum Circles
- 1050: Commercially pure (≥99.5% Al). Excellent corrosion resistance, electrical and thermal conductivity, and highest ductility among common aluminum alloys. Limited strength; suitable for severe forming (deep drawing) where strength is less critical.
- 3003: Alloyed with manganese (~1.0–1.5%), giving better strength while retaining good formability and corrosion resistance. Widely used where moderate strength is required along with formability and weldability.
Chemical Composition
1050 Aluminum (EN AW-1050, Al99.5)
| Element | Si | Fe | Cu | Mn | Mg | Zn | Ti | Al |
|---|---|---|---|---|---|---|---|---|
| Typical (%) | 0.25 max | 0.40 max | 0.05 max | 0.05 max | 0.05 max | 0.05 max | 0.03 max | Bal. (~99.5) |
Notes: Values are maximum allowable (%) unless otherwise specified. 1050 is essentially pure aluminum; standards may specify minimum Al content (≥99.5%).
3003 Aluminum (EN AW-3003 / ASTM B209 equivalent)
| Element | Si | Fe | Cu | Mn | Mg | Zn | Ti | Others (each) | Others (total) | Al |
|---|---|---|---|---|---|---|---|---|---|---|
| Typical (%) | 0.6 max | 0.7 max | 0.05–0.20 | 1.0–1.5 | 0.10 max | 0.10 max | 0.15 max | 0.05 max | 0.15 max | Bal. (~97.0–98.5) |
Notes: 3003 targets manganese addition for strengthening (≈1.0–1.5%). Exact ranges depend on specific standard (ASTM/EN/JIS).
Mechanical Properties and Temper Designations
Aluminum circles are supplied in various tempers affecting strength and ductility. Typical tempers used for cookware and sign substrates are O, H12, H14, H18, H22, H24 depending on drawing and strength needs.
Typical Mechanical Properties
| Alloy | Temper | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Hardness (HB) |
|---|---|---|---|---|---|
| 1050 | O (annealed) | 55–80 | 25–40 | 30–40 | 15–25 |
| 1050 | H14 (cold worked) | 80–100 | 40–60 | 10–15 | 25–35 |
| 3003 | O (annealed) | 80–105 | 35–55 | 20–30 | 25–40 |
| 3003 | H14 (cold worked) | 115–140 | 65–90 | 8–12 | 40–55 |
Notes: Values are approximate typical ranges; refer to specific standard or mill certificates for exact values. H12/H14/H18 etc. indicate increasing levels of strain hardening.
Tempering / Heat Treatment and Work Hardening
Aluminum non-heat-treatable alloys (1xxx and 3xxx series) derive strength from cold working. Common tempers for circles:
| Temper | Meaning | Typical Use |
|---|---|---|
| O | Annealed (soft) | Maximum ductility for deep drawing cookware (pots, pans, deep shapes) |
| H12 | Quarter-hard | Some formability with moderate strength |
| H14 | Half-hard | Moderate strength for shallow drawn parts and sign blanks |
| H18 | Full-hard | High strength, limited formability (flat sign plates, stiff substrates) |
| H22/H24 | Hard tempers stabilized | Combination of pre-aged or stabilized hardness for consistent forming |
Implementation: Annealing is typically done at temperatures around 350–420°C depending on thickness and alloy, then controlled cooling to achieve O temper. Cold rolling to specified reduction yields H-tempers.
Technical Specifications (Typical for Aluminum Circle Supply)
| Parameter | Typical Range / Value |
|---|---|
| Thickness | 0.10 mm – 6.0 mm (common for cookware 0.6–2.0 mm; signs 0.8–2.5 mm) |
| Diameter | 60 mm – 1500+ mm (custom diameters available) |
| Thickness Tolerance | ±0.02 mm to ±0.10 mm depending on thickness and customer spec |
| Diameter Tolerance | ±0.2 mm to ±2.0 mm depending on diameter and manufacturing method |
| Surface Finish | Mill finish, anodized, polished, bright annealed, pre-painted, PVDF coated |
| Edge Condition | Deburred, smooth or with slight burr depending on process |
| Flatness | Specified by customer; typically measured as mm per specified length |
| Coil Source | Cold-rolled sheet/coil or bright annealed coil |
| Standard Packaging | Wooden crates, plastic film interleaving, plywood rounds, pallets |
| Certification | Mill test report (MTC), Chemical & Mechanical test certificates available |
Implementation Standards & References
Typical standards used for production, testing, and acceptance:
| Area | Standard / Specification |
|---|---|
| Material Composition & Mechanical | ASTM B209, EN 573, EN 755 for extrusions/sheets |
| Alloy Designation | EN AW-1050A (Al99.5), EN AW-3003 |
| Surface treatment | ASTM B580 (Anodizing), ISO 7599 |
| Testing | ASTM E8 (tensile test), EN 10204 (inspection documents) |
| Reflective Sheeting on Signs | ASTM D4956 (for retroreflective sheeting applied to sign faces) |
| Outdoor Durability | ISO 9223 (corrosion), ASTM G154 (UV exposure) |
Note: Exact standard numbers depend on regional requirements; suppliers should provide compliance documentation on request.
Functional Advantages per Application
Cookware (pots, pans, deep-drawn goods)
- High ductility (especially 1050 O) enables deep drawing without cracking.
- Uniform thickness circles ensure consistent wall thickness after forming.
- Good thermal conductivity (1050 > 3003) provides quick, even heating in cookware. Typical thermal conductivity: 1050 ≈ 220–230 W/m·K; 3003 slightly lower due to alloying.
- Corrosion resistance ensures long life with food contact (anodizing can enhance surface hardness and abrasion resistance).
- Surface finishes: bright annealed for polished look, anodized for wear resistance, or coated for non-stick applications.
Traffic Signs
- 3003 offers higher strength and dent resistance while retaining formability for sign blanks.
- Corrosion resistance and ability to accept coatings (PVDF, paint) make both alloys suitable for outdoor use.
- Flatness and stiffness (thicker, H18/H24 tempers) are important to prevent buckling in large sign faces.
- Compatibility with retroreflective sheeting (adhesion and thermal stability) is critical; surface pre-treatment improves bonding.
- Lightweight discs reduce installation load on poles and brackets.
Typical Processing Steps for Aluminum Circles
- Coil/Sheet selection: Choose alloy and temper per application.
- Cutting/Blanking: Progressive die blanking or laser cutting to produce circles.
- Edge deburring: Mechanical or tumbling to remove sharp edges.
- Annealing (if required): Bright or full anneal for O temper to improve formability.
- Surface treatment: Anodizing, polishing, cleaning, or pre-painting as required.
- Packaging: Interleaving with paper or plastic, stacking, and crating to protect surface.
Quality Control & Testing
- Chemical composition verification via spectrometry (ICP-OES or OES).
- Mechanical testing (tensile, yield, elongation) per ASTM/EN methods.
- Thickness and diameter measurement using calibrated gauges.
- Surface inspection for defects, scratches, pits; adhesion tests for coatings.
- Flatness and dimensional tolerances inspection.
- Certification: Mill Test Certificate (EN 10204/3.1 or 2.2 depending on customer requirement).
Selection Guidance
- Choose 1050 aluminum circles when the highest formability/ductility and thermal conductivity are needed — e.g., deep-drawn cookware and polished finishes.
- Choose 3003 aluminum circles for better strength, dent resistance, and moderate formability — e.g., traffic sign blanks that require more stiffness or welded attachments.
- Tempers:
- Use O temper (annealed) for deep drawing and severe forming.
- Use H14/H18 for moderate forming and increased strength.
- Use H18/H24 or thicker gauges for flat, stiff sign faces.
Typical Physical Properties
| Property | 1050 | 3003 |
|---|---|---|
| Density (g/cm3) | 2.71 | 2.73 |
| Melting Range (°C) | 660 approx. | 640–650 approx. |
| Thermal Conductivity (W/m·K) | 220–235 | 140–170 |
| Electrical Conductivity (% IACS) | ~61–63% | ~20–30% |
| Modulus of Elasticity (GPa) | 69 | 69 |
Notes: Thermal/electrical conductivities vary with alloying and temper.
Practical Considerations for Buyers
- Request mill test certificates (chemical and mechanical) and sample circles before large orders.
- Specify exact diameter, thickness, tolerance, edge condition, surface finish, and temper in the purchase order.
- For cookware intended for food contact, ensure compliance with relevant food safety regulations in target markets.
- For traffic signs, coordinate with specifiers of reflective sheeting to ensure compatibility and adhesion (pre-treatment, primer requirements).
- Consider finishing (anodizing for cookware for durability; pre-painting or PVDF coating for signs) as a value-add.
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