When choosing aluminum foil for packaging, insulation, or electronics, it’s essential to know more than just the alloy—understanding the temper (grade) can make all the difference in performance, durability, and usability.
This guide introduces the most common aluminum foil grades—O, H14, H18, H24, H26—and explains their properties, processing methods, and best-use scenarios.
1. What Is Aluminum Foil Temper?
Aluminum foil temper refers to the mechanical condition of the material after processing. It describes how soft or hard the foil is, based on the amount of cold working and heat treatment applied.
Two Main Categories of Temper:
O Temper (Annealed / Soft): Fully annealed aluminum, very soft, with excellent formability.
H Temper (Strain-Hardened): Cold-worked aluminum, with varying levels of strength and hardness (e.g., H14, H18).
2. Common Aluminum Foil Grades & Their Properties
| Temper Code | Name | Processing | Main Features | Typical Applications |
|---|---|---|---|---|
| O | Soft / Annealed | Fully annealed | Maximum ductility, very soft | Household foil, pharmaceutical foil, cable wrap |
| H12 | Quarter Hard | Cold-rolled | Lower strength, good formability | Seals, labels, flexible packaging |
| H14 | Half Hard | Cold-rolled | Medium strength, good balance | HVAC fins, lids, packaging foil |
| H18 | Full Hard | Cold-rolled | High strength, low elongation | Battery foil, capacitor foil, electronics |
| H24 | 3/4 Hard | Cold-rolled + slight anneal | Stronger than H14, still formable | Semi-rigid containers, automotive foil |
| H26 | Extra Hard | Cold-rolled + minimal anneal | High strength, slightly more ductile than H18 | Battery foil, blister foil, composite panels |
3. How Are Tempers Created?
✅ Cold Working
Aluminum is cold-rolled to increase strength by distorting its grain structure. This produces H-tempers.
✅ Annealing
A heat treatment process that softens aluminum by relieving internal stress, producing the O temper.
4. Industry Applications by Foil Temper
| Industry | Recommended Temper | Why |
|---|---|---|
| Household Foil | O | Easy to fold, soft, safe for direct food contact |
| Pharmaceutical Foil | O | Deep drawing capability and sterile sealing |
| HVAC / Heat Exchangers | H14 / H24 | Good rigidity and structural strength |
| Battery & Capacitors | H18 / H26 | High tensile strength, stable under electrical load |
| Semi-Rigid Containers | H22 / H24 | Balance of strength and formability |
| Industrial Wraps | H14 / H18 | Durable, heat-resistant, easy to process |
5. Choosing the Right Foil Grade
Use this quick guide to select the right aluminum foil temper for your application:
🟢 Need maximum flexibility? → Choose O temper
🔵 Need a mix of strength and forming ability? → Choose H14 or H24
🔴 Need high strength and durability? → Choose H18 or H26
6. Final Thoughts: Choose Smart, Use Right
The temper of aluminum foil determines its true capabilities. Whether you need deep-draw performance, structural rigidity, or high electrical conductivity, selecting the correct temper is crucial for performance and cost-effectiveness.
At Gengfei Steel, we supply a full range of aluminum foil tempers and alloys to meet your exact application needs. Contact us today for expert support and custom solutions.
📞Contact Us
Gengfei Steel – Your Trusted Aluminum Foil Supplier
📧 Email: [email protected]
📞 WhatsApp / Phone: +86 191 3986 3252
🌐 Website: www.gengfeisteel.com
Gengfei Provides High Quality Aluminum Foil
Please let us know your procurement requirements, and we will quickly tailor the most competitive quotation for you.
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