Hot rolled 1050 and 1060 aluminum circles are widely used in the cookware industry due to their excellent formability, corrosion resistance, thermal conductivity, and food safety.
Aluminum circles are flat, round discs usually produced by blanking and edge-trimming from coil or sheet, then hot rolled or cold worked as required. Hot rolled 1050 and 1060 aluminum circles are popular for pots, pans, lids, and other cookware components because they balance mechanical properties, deep-draw capability, and cost-effectiveness.
- 1050 and 1060 are commercial-purity aluminum alloys belonging to the 1xxx series.
- These alloys are essentially pure aluminum with controlled amounts of impurities and small additions.
- Hot rolling improves workability and can be followed by annealing or cold work depending on forming requirements.
Functions in Cookware
- Excellent thermal conductivity — enables fast and even heat distribution across cookware surfaces.
- High formability and deep-drawing capability — allows efficient stamping and drawing into complex shapes (pots, pans, lids).
- Corrosion resistance — stable in food environments and with common household acids.
- Food-safe — minimal alloying elements reduce risk of reactions; compliant grades are suitable for direct food contact when finished properly.
- Lightweight — reduces overall cookware weight for ease of use.
- Cost-effective — 1xxx series alloys are among the most economical aluminum grades for high-volume cookware manufacturing.
Typical Applications
- Cookware bodies (pots, saucepans, stockpots)
- Frying pans and skillets (as inner/outer skins or lids)
- Steamers and cookware inserts
- Lid discs and domes
- Heat spreaders and bottoms (often laminated or clad with other alloys or stainless steel)
- Disposable foil-like cookware components (where thicker, durable discs are needed)
- 1050: Aluminum with a minimum 99.5% Al content. Known for excellent ductility and formability.
- 1060: Slightly higher purity with minimum 99.6% Al content. Offers incremental improvements in conductivity and corrosion resistance.
- Both alloys are used interchangeably in many cookware applications; selection depends on exact forming needs, cost, and finishing requirements.
Implementation Standards
Common standards and specifications that apply to 1050 / 1060 aluminum circles for cookware include:
- ASTM B209 — Aluminum and Aluminum-Alloy Sheet and Plate
- EN 573 / EN 485 — Chemical composition and mechanical properties of aluminum and its alloys (European)
- JIS H4000 / JIS H4003 — Japanese Industrial Standards for aluminum plates and sheets
- GB/T 3880 / GB/T 3190 — Chinese standards for aluminum alloy chemical composition and temper designations
- FDA 21 CFR (where applicable) and EU regulations for materials in contact with food — for finished cookware compliance
Note: Specific cookware manufacturers often follow additional food-contact finishing and coating standards (e.g., anodizing per ISO 10074, PTFE coatings qualified to non-stick coating standards), as well as surface cleaning, passivation, and packaging protocols.
Chemical Composition
Below are typical chemical composition ranges for 1050 and 1060 aluminum alloys (wt.%). These follow common international standards (EN / ASTM / GB / JIS ranges approximate).
| Element | 1050 (Typical, wt.%) | 1060 (Typical, wt.%) |
|---|---|---|
| Aluminum (Al) | Balance (≥ 99.5%) | Balance (≥ 99.6%) |
| Silicon (Si) | ≤ 0.25 | ≤ 0.25 |
| Iron (Fe) | ≤ 0.40 | ≤ 0.35 |
| Copper (Cu) | ≤ 0.05 | ≤ 0.05 |
| Manganese (Mn) | ≤ 0.05 | ≤ 0.05 |
| Magnesium (Mg) | ≤ 0.03 | ≤ 0.03 |
| Zinc (Zn) | ≤ 0.05 | ≤ 0.03 |
| Titanium (Ti) | ≤ 0.03 | ≤ 0.03 |
| Other elements (each) | ≤ 0.03 | ≤ 0.03 |
| Other elements (total) | ≤ 0.10 | ≤ 0.05 |
Notes:
- Actual certified values depend on the standard and mill test report.
- Purity margins vary slightly by production route and country standard.
Temper Designations and Forming Conditions
1xxx-series alloys are non-heat-treatable; mechanical properties are controlled by cold working (temper). For cookware, common tempers and processing methods include:
| Temper | Description | Typical Use in Cookware |
|---|---|---|
| O | Annealed (soft) | Deep drawing, severe forming, spinning |
| H12 | Strain-hardened, quarter-hard | Moderate forming, moderate stiffness |
| H14 | Strain-hardened, half-hard | Stamping with moderate drawing |
| H16 | Strain-hardened, hard | Shallow drawing, retain shape |
| H18 | Strain-hardened, full-hard | Coil-fed pressing, non-draw components |
| T4 (rare) | Solution heat-treated and naturally aged | Not typical for 1xxx; not commonly used |
Processing route for hot rolled circles:
- Hot rolling to required gauge
- Annealing (O temper) to maximize formability if deep drawing is required
- Cold rolling/skin pass to required thickness and surface finish
- Blanking/laser cutting to circle blank
- Edge trimming and possibly spinning or further cold forming
- Final anneal or controlled hardening to reach the desired temper (H12–H18) based on forming and final part stiffness needs
Mechanical Properties (Typical)
Mechanical properties vary with temper. Typical ranges for 1050 / 1060 alloys:
| Property | O Temper | H14 Temper | H18 Temper |
|---|---|---|---|
| Tensile Strength, MPa | 40–60 | 55–95 | 90–120 |
| Yield Strength (0.2% offset), MPa | 15–35 | 20–50 | 40–90 |
| Elongation (%) | 30–40 | 10–25 | 3–10 |
| Hardness (HB) | 20–35 | 30–45 | 40–60 |
| Density (g/cm3) | 2.70 | 2.70 | 2.70 |
| Thermal Conductivity (W/m·K) | 220–237 | 220–237 | 220–237 |
| Electrical Conductivity (% IACS) | ~57–63 | ~57–63 | ~57–63 |
Notes:
- Values are indicative; check mill certificates and relevant standards for exact figures.
- Thermal conductivity is a strong advantage of these high-purity alloys for cookware.
Typical Dimensions & Tolerances for Aluminum Circles
Manufacturers supply circles in a range of diameters and thicknesses. Typical sizes for cookware applications:
| Parameter | Typical Range |
|---|---|
| Diameter | 50 mm — 1000+ mm (custom) |
| Thickness | 0.3 mm — 6.0 mm (common for cookware 0.4–2.5 mm) |
| Thickness Tolerance | ±0.02 mm to ±0.10 mm (depending on thickness) |
| Flatness & Runout | Per customer specification, controlled for stamping/assembly |
| Edge Condition | Deburred, chamfered, or as-blanked; edge radius available on request |
| Surface Finish | Mill finish, bright annealed, ground, or anodized per requirement |
Corrosion Resistance & Food Safety
- 1050/1060 have excellent natural corrosion resistance in most food preparation environments.
- For enhanced scratch resistance and hygiene, anodizing is common (produces Al2O3 layer) — complies with food contact standards when process parameters are controlled.
- When using coatings (PTFE, ceramic), surface preparation (cleaning, anodizing, etching) must follow the coating supplier’s recommendations.
- Regulatory compliance: final products intended for food contact should follow local regulations (FDA, EU 1935/2004, national food-contact standards). Metal purity, surface treatment, and coatings must be certified where required.
Fabrication & Forming Considerations
- Deep drawing and spinning: O temper or soft-annealed material is recommended initially to avoid cracks; subsequent anneals may be required between forming steps.
- Springback: low in 1xxx alloys; temper selection influences final dimensional stability.
- Welding and joining: aluminum requires appropriate techniques (TIG/MIG for thicker parts, spot welding for certain assemblies, brazing with proper flux). Post-weld annealing may affect properties.
- Joining to other materials: often clad with stainless steel or copper for composite cookware bottoms — bonding and diffusion processes require precise metallurgical control.
- Surface finishing: anodizing, polishing, brushing, coating (non-stick) — surface cleanliness and roughness control are crucial for coating adhesion.
Quality Control & Testing
QC tests for cookware circles include:
- Chemical composition (OES or ICP analysis)
- Thickness and dimensional inspection (calipers, micrometers, optical)
- Mechanical testing (tensile, hardness)
- Conductivity and thermal testing (as required)
- Visual inspection for surface defects, pits, inclusions
- Flatness and runout checks (for assembly fit)
- Coating adhesion, thickness, and food-safety certification (if coated/anodized)
- Packaging and corrosion protection checks for shipment
Advantages & Limitations
Advantages:
- Excellent thermal conductivity and formability
- High corrosion resistance for food contact
- Cost-effective for high-volume production
- Lightweight and recyclable
Limitations:
- Lower strength compared with alloyed series (e.g., 3xxx, 5xxx) — may require thicker gauge or reinforcement for heavy-duty cookware
- Surface scratch sensitivity unless anodized or coated
- Not heat-treatable (strengthening limited to cold work)
| Item | Specification / Typical Value |
|---|---|
| Alloy | 1050 / 1060 (1xxx series) |
| Temper | O / H14 / H18 (per part requirements) |
| Thickness | 0.4 – 2.5 mm (typical cookware) |
| Diameter | Custom (50 – 1000 mm+) |
| Chemical Purity | ≥ 99.5% (1050), ≥ 99.6% (1060) Al |
| Tensile Strength | 40–120 MPa (depending on temper) |
| Thermal Conductivity | 220–237 W/m·K |
| Density | 2.70 g/cm3 |
| Surface Finish | Mill / Bright annealed / Anodized / Coated |
| Standards | ASTM B209, EN 573/485, GB/T 3880, JIS H4000 |
Selection Guide for Cookware Manufacturers
- Choose 1050/1060 O temper for deep-drawn pots and complex shapes; anneal as needed between operations.
- Use H14–H18 tempers for stamped lids, shallow-drawn pans, and parts requiring dimensional stability.
- Consider anodizing for scratch resistance and food-safety passivation; ensure compliance with regional food-contact regulations.
- For enhanced bottom heat distribution, consider clad or laminated constructions (e.g., aluminum circle bonded to stainless steel disc).
- Work closely with material suppliers to obtain mill test certificates (chemical, mechanical, surface finish) and to specify tolerances that meet forming and assembly needs.
