The 3003-H18 aluminum flat sheet is a rigid, non-heat-treatable alloy panel belonging to the 3xxx series. By alloying commercial aluminum with approximately 1.0% to 1.5% manganese, it gains a 20% increase in tensile strength over pure 1100 aluminum. The "H18" designation means the sheet has been cold-rolled to a "Full Hard" temper.
At GNEE, we supply this highly durable, corrosion-resistant flat sheet to manufacturing hubs across Mexico, specifically targeting applications that require flat structural integrity, superior moisture resistance, and tight dimensional tolerances without the need for deep forming.
Below is the unedited, direct factory data you need to specify and source 3003 aluminum sheets correctly for your Mexican production lines.
Chemical Composition of 3003 Aluminum Flat Sheet
Whether you are ordering a full hard panel or a custom 3003-O aluminum flat panel (annealed), the chemical makeup must adhere to ASTM B209 standards.
Here is the precise chemistry verified on our Mill Test Certificates (MTC):
| Element | Symbol | Required Percentage (%) | Factory Metallurgical Purpose |
| Aluminum | Al | ~96.8 - 99.0 | The base matrix material. |
| Manganese | Mn | 1.0 - 1.5 | The primary strengthener. Increases rigidity without compromising the alloy's natural rust resistance. |
| Iron | Fe | ≤ 0.7 | Impurity limit. Strictly controlled at the GNEE mill to ensure the sheet does not crack during the high-speed cold rolling process. |
| Silicon | Si | ≤ 0.6 | Impurity limit. Monitored alongside iron. |
| Copper | Cu | 0.05 - 0.20 | Added in trace amounts to provide a slight boost to overall tensile strength. |
| Zinc | Zn | ≤ 0.10 | Restricted to guarantee maximum resistance against salt and humidity (crucial for coastal Mexican plants). |
Mechanical Limits of 3003-H18 Aluminum Plate
H18 means the metal is "Full Hard." It is incredibly stiff. If you attempt to run a 3003-H18 aluminum plate through a CNC press brake for a 90-degree bend, or try to deep-stamp it, the metal's outer grain structure will immediately crack and tear.
Here are the realistic mechanical limits:
| Temper | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) | Bending & Machining Reality |
| H18 (Full Hard) | 190 - 200 | 185 | ~4% | Maximum rigidity. Used exclusively for completely flat panels or very gentle, large-radius curving. Will snap if bent sharply. |
| H14 (Half Hard) | 150 | 145 | 8% - 16% | The industry standard for standard sheet metal. Easily handles 90-degree bends without fracturing. |
| O (Soft/Annealed) | 110 | 40 | ~30% | Maximum ductility. Mandatory for severe deep drawing and complex 3D stamping. |
Applications for 3003-H18 Aluminum Flat Panel in Mexico
Because of Mexico's booming manufacturing sector, the demand for wholesale 3003-H18 aluminum flat sheet is massive. However, it must be used correctly. Here is where GNEE clients in Monterrey, Tijuana, and Queretaro actually deploy this full-hard material:
1. Flat Architectural Façades and Cleanrooms
In humid coastal areas like Baja California or Cancun, builders need exterior panels that will not rust. 3003-H18 provides a perfectly flat, rigid surface for architectural curtain walls. Furthermore, in pharmaceutical manufacturing facilities across Mexico, these flat panels are used as cleanroom wall cladding because they are non-toxic, easy to sanitize, and won't warp.
2. Automotive Heat Shields (Flat Profiles)
While complex, stamped auto parts require softer tempers, flat thermal barriers and battery compartment base plates utilize 3003-H18. The alloy conducts heat exceptionally well (193 W/m-K) and provides high structural stiffness with very low weight.
3. HVAC and Condenser Fin Stock
For commercial air conditioning units, 3003-H18 is often slit into thin flat sheets to create rigid heat exchanger fins. The full-hard temper ensures the fins do not collapse under high air pressure, while the manganese content resists corrosion from continuous condensation.
SMM Pricing for Wholesale 3003 Aluminum Sheet
Current SMM (Shanghai Metals Market) Base Price + Factory Processing Fee + Sea Freight to Mexico.
Logistics: The Manzanillo/Ensenada Route
Ocean freight from Shanghai to Manzanillo or Ensenada takes approximately 20 to 30 days. During this time, trapped container humidity can cause "white rust," destroying bare aluminum. GNEE utilizes strict marine-grade packaging for all Mexico aluminum sheet import orders:
- Sheets are perfectly stacked and interleaved with acid-free paper.
- Wrapped in heavy-duty waterproof kraft paper.
- Encapsulated in plastic shrink film loaded with industrial silica gel desiccants.
- Secured with steel bands onto ISPM-15 fumigated wooden pallets, ensuring rapid and compliant customs clearance under Mexican import regulations.
FAQ
Q1: Is 3003-H18 aluminum flat sheet bendable?
No. The H18 temper indicates the metal is "Full Hard." It has an elongation rate of roughly 4%. If you attempt to bend it at a 90-degree angle on a press brake, the material will crack and fail. If your production requires bending, you must order 3003-H14 (Half Hard) or 3003-O (Annealed) flat sheets.
Q2: Can I use 3003-H18 for pharmaceutical blister packaging?
No. Pharmaceutical blister packs require extreme flexibility to be formed into cavities and sealed. For blister packaging, you need pure aluminum foil (like 8011-O or 8021-O temper), not a rigid 3003-H18 flat sheet. However, 3003-H18 flat sheets are widely used to construct the sterile cleanroom walls inside pharmaceutical plants.
Q3: Does 3003 aluminum rust in Mexico's coastal environments?
No. Aluminum does not contain iron, so it cannot rust. The 3003 alloy contains manganese, which gives it outstanding atmospheric corrosion resistance. When exposed to the salty, humid air of coastal Mexico, it instantly forms a microscopic, dense aluminum oxide barrier that seals the metal, making it ideal for outdoor architecture.
Q4: How does GNEE price its aluminum compared to local Mexican distributors?
Local distributors in Mexico hold inventory and add significant markups to cover their warehousing and LME hedging risks. GNEE is a direct manufacturer. We price your bulk order based on the live SMM (Shanghai Metals Market) ingot price plus our direct mill processing fee. Buying factory-direct typically yields significant cost savings for high-volume IMMEX manufacturers.
