When manufacturing with the widely popular 3003 aluminum alloy (an aluminum-manganese alloy known for excellent corrosion resistance), selecting the right temper is critical for your production line's success. Two of the most commonly specified and confused tempers are H14 and H24. If your engineers specify H14 but your press brake operators are complaining about the metal cracking on 90-degree bends, you are facing a classic temper selection problem.
The main difference between 3003 H14 and 3003 H24 aluminum lies in their processing condition and resulting ductility. Both are strain-hardened to the exact same strength level (half-hard). However, 3003 H14 is only strain-hardened, retaining high internal stress. 3003 H24 is strain-hardened and then partially annealed, which relieves internal stress and provides significantly better formability.
- 3003 H14 = Directly strain-hardened. High internal stress, good for flat panels.
- 3003 H24 = Strain-hardened + partially annealed. Same strength, but much easier to bend and form without cracking.
Choosing the right material dictates your scrap rate. In this comprehensive B2B guide, we will break down the exact mechanical properties, the underlying heat treatment differences, and real-world industrial applications to help you make the right purchasing decision.
Are you experiencing cracking or inconsistent springback during sheet metal bending? Don't let the wrong temper ruin your production run. Contact GNEE's engineering team today for a free technical consultation and request a 3003 H24 aluminum sample to test on your own equipment.
What is 3003 H14 Aluminum Sheet?
To understand the H14 temper, you must look at how it is rolled at the mill. The "H" stands for strain hardening (also known as cold working). The first digit "1" means the metal was cold worked to its final dimensions with absolutely no thermal treatment applied afterward. The second digit "4" designates the degree of hardness, which is "half-hard."
Key features of 3003 H14 aluminum:
- Cold Worked Only: The metal is rolled at room temperature to increase its strength.
- High Internal Stress: The grain structure is compressed and remains tense.
- Moderate Ductility: It can be bent, but it requires careful attention to the bending radius.
- Stiff and Flat: Excellent for applications where the sheet needs to remain flat and rigid under minor loads.
What is 3003 H24 Aluminum Plate?
The "H24" designation tells a different processing story. The "H" still stands for strain hardening, and the "4" still means "half-hard." However, the first digit "2" means the metal was strain-hardened and then partially annealed.
At the mill, the aluminum is intentionally cold-rolled to a hardness level higher than half-hard (often approaching H18 full hard). Then, it is placed in a furnace and heated at a precise, moderate temperature. This "partial annealing" brings the strength back down to the half-hard level while completely transforming the material's internal behavior.
Key features of 3003 H24 aluminum:
- Strain-Hardened + Partially Annealed: A two-step process.
- Same Strength as H14: It meets the identical tensile and yield strength requirements.
- Lower Internal Stress: The heat treatment relaxes the compressed grain structure.
- Better Formability: It stretches and bends much more willingly than H14 without fracturing.
3003 H14 vs 3003 H24 Aluminum Comparison Overview
Here is a quick reference table comparing how these two tempers behave on a factory floor.
| Property | 3003 H14 Aluminum | 3003 H24 Aluminum |
| Temper Type | Strain Hardened Only | Strain Hardened + Partial Anneal |
| Strength Level | Half-Hard | Half-Hard |
| Ductility | Moderate | Better |
| Residual Stress | Higher | Lower |
| Formability | Good (Simple bends) | Better (Complex shapes, tighter bends) |
| Surface Stability | Normal | More stable after intensive forming |
3003 H14 vs 3003 H24 Aluminum Mechanical Properties
When purchasing managers look at a Mill Test Certificate (MTC), they often see that H14 and H24 look virtually identical in terms of strength. The secret lies in the elongation percentage.
| Mechanical Property | 3003 H14 Temper | 3003 H24 Temper |
| Tensile Strength (Rm) | 140 – 180 MPa | 140 – 180 MPa |
| Yield Strength (Rp0.2) | ≥ 115 MPa | ≥ 115 MPa |
| Elongation (A50mm) | ~ 5% – 10% | ~ 8% – 12% |
Data Analysis: Notice that the Tensile and Yield Strengths are exactly the same. However, the Elongation of H24 is consistently higher. That extra 3% to 4% of elongation is the difference between a clean 90-degree fold and a cracked edge on your press brake.
The Problem with 3003 H14
Springback and Micro-Cracking
Because 3003 H14 is only cold-worked, the material holds a massive amount of residual energy (internal stress). When a press brake forces an H14 sheet into a V-die to create a bend, the outer edge of the curve stretches aggressively. Because the internal grains are already tight from cold rolling, they resist this stretching.
This results in two issues:
- High Springback: When the die releases, the metal tries to return to its flat state. Operators must constantly adjust the machine to over-bend the metal to achieve the correct angle.
- Micro-Cracking: If the bending radius is too tight, the tense outer fibers of the H14 sheet will snap, creating a rough, orange-peel texture or a full fracture along the bend line.
The Solution with 3003 H24
Stress Relief
The partial annealing process used to create 3003 H24 relaxes those internal grains. When the press brake bends an H24 sheet, the metal flows into the die smoothly. The relaxed grains stretch without snapping. Springback is significantly reduced and highly predictable, and the risk of cracking on sharp bends is virtually eliminated.
Applications of 3003 H14 Aluminum Sheet
Because it is stiffer and cheaper to produce (no furnace time required), H14 is ideal for applications where the metal stays relatively flat or involves very gentle curves:
- Roofing Sheets and Siding: Corrugated panels where the high internal stress helps maintain the panel's rigidity against wind.
- Storage Tanks: Large cylindrical chemical or water tanks that only require gentle rolling, not sharp bending.
- Cladding Panels: Flat architectural facades.
- General Sheet Metal: Flat blanks, stamped washers, and basic brackets.
Applications of 3003 H24 Aluminum Plate
Because it is stress-relieved and highly ductile, H24 is the premium choice for complex fabrication:
- Deep Drawing Parts: Housings and enclosures that must be punched and drawn into a die without tearing.
- Kitchenware: Pots, pans, and baking sheets where the material undergoes significant shaping.
- Heat Exchangers and Radiators: Fins and tubes that require extensive forming.
- HVAC Components: Complex ducting and housings requiring sharp folds and interlocking joints.
How to Choose Between 3003 H14 and H24?
If you are writing an RFQ (Request for Quote) and are unsure which temper to specify, use this checklist:
Choose 3003 H14 Aluminum if:
- You are manufacturing flat panels, roofing, or basic enclosures.
- No sharp bending, deep drawing, or complex forming is required.
- You need a slightly lower material cost (as it skips the annealing step).
- High rigidity in a flat state is your primary concern.
Choose 3003 H24 Aluminum if:
- Your design requires tight 90-degree bends, hemming, or folding.
- You are experiencing cracking issues with your current H14 supply.
- You want to reduce springback and make CNC press brake setup easier.
- You are manufacturing deep-drawn parts or complex HVAC components.
Why Choose GNEE as Your Chinese Aluminum Supplier?
- Full Tempers Available: We supply the complete 3003 series, including O (annealed), H12, H14, H24, and H18.
- Large Stock & Fast Delivery: We maintain massive inventories of 3003 aluminum coil and sheet, ready for standard shipment or custom processing.
- Custom Sizes and Cutting Service: We offer precision slitting and cut-to-length services to provide blanks that fit directly into your machines, minimizing waste.
- Support Mixed Alloy Orders: Optimize your cash flow and shipping costs by mixing 3003 with 5052, 5083, or 6061 aluminum in a single container.
- Global Export Expertise: We ship to over 100 countries, providing strict seaworthy packaging (fumigated wooden pallets + waterproof barriers) to ensure your material arrives perfectly flat and oxidation-free.
Get a Quote Now
Stop letting temper confusion dictate your scrap rates. Whether you need the cost-effective rigidity of 3003 H14 or the superior formability of 3003 H24, GNEE guarantees precision quality and fast delivery.
Ready to compare prices? Send us your size list and required temper today for a factory-direct quotation.
Contact GNEE for:
Free technical support to confirm your temper selection.
Competitive, transparent volume pricing.
Sample availability and detailed Mill Test Certificates (MTC).
