Aluminum Alloy Knowledge and FAQ鋁合金技術知識與常見問答

Aluminum is light. Its density is about 2.7 g/cm³, which is about one-third that of steel. It conducts electricity and heat well, resists corrosion well, is easy to machine and join, and can be recycled.

The 1000 series (pure aluminum) forms, welds, and resists corrosion well, but its strength is lower. The 3000 series (aluminum-manganese) is a little stronger than the 1000 series. It is used for general equipment, building, and containers. The 5000 series (aluminum-magnesium, such as 5052) has medium strength. It forms, welds, and resists corrosion well. The 6000 series (such as 6061) is heat-treatable. T6 treatment raises its strength. It is used for structures and jigs and fixtures. To choose the right one for your use, please contact us.

All three are 1000 series pure aluminum. They form well, weld well, and resist corrosion well. The aluminum purity under CNS 2253 (Taiwan national standard) is A1050 at 99.50% or more, A1070 at 99.70% or more, and A1100 at 99.00% or more.

A5052 is an aluminum-magnesium alloy. It is a typical medium-strength aluminum alloy. It forms well, welds well, and resists corrosion well. Common uses include transportation, optical equipment, computer housings, LED back panels, laptops, and beverage cans.

5052 is non-heat-treatable. It gets its strength from cold rolling. It forms well and welds well. 6061 is heat-treatable. In the T6 temper it has high strength, but it does not bend as well. After welding, the strength drops in the heat-affected zone (the area next to the weld).

1000 series (A1050, A1070, A1100, A1N30), 3000 series (A3003, A3004), 5000 series (A5052, A5182), and 6000 series (A6061). If the material you need is not listed, please call us.

Yes. They are the same grade written in different systems. Aluminum alloys are usually written as A plus four digits (for example, A5052). The U.S. Aluminum Association (AA) writes it as 5052. UNS (Unified Numbering System) writes it as A9 plus four digits (A95052). Europe writes it as EN AW-5052. Here is how the grades we supply compare.

Not exactly. They are close matches. The Aluminum Association registers 1050 and 1050A as two different alloys, and 1070 and 1070A as two different alloys. Their main composition limits are close, but the upper limits for some trace elements are slightly different. If you must meet a specific standard, use the grade named in that standard.

O is the soft condition after annealing. It is often called soft temper. In the H group, H1X means the metal was only strain-hardened (made harder by working it) and was not heat-treated. H3X means it was strain-hardened and then stabilized. T6 means the metal was solution heat-treated, then artificially aged to harden it, without any cold working. For more on aluminum tempers, see the China Steel Aluminum page on H tempers: https://www.csalu.com.tw/en/Product2-03.html

Temper describes the mechanical working or heat treatment that aluminum alloy goes through during manufacturing (such as rolling and heat treatment), and how much of it. These steps give the metal the hardness, strength, ductility, and corrosion resistance it needs. For more on aluminum tempers, see the China Steel Aluminum website: https://www.csalu.com.tw/en/Product2-01.html

These are temper codes. They show how the metal was processed and how hard it is. Under CNS 2253, the specified tensile strength is 170–215 for O, 215–265 for H32, 235–285 for H34, and 285 or more for H39 (all in N/mm²). A bigger number means harder metal and higher strength.

Annealing aluminum is a heat treatment. The alloy is heated to a set temperature, held there for a time, and then cooled slowly. Heating lets the metal’s grain structure recover and recrystallize into soft, low-stress grains. Annealing removes the internal stress left by cold working or casting, lowers the hardness, and restores ductility.

Yes. When you place your order, please tell us that you need annealing. The annealing furnace has size limits, mainly for length and width, or for coil size. It also needs specific packing.

CNS 2253 (H3025) is the Taiwan national standard for aluminum and aluminum alloy sheet, coil, and plate. It covers aluminum sheet, alloy plate, coil, and circles made by hot rolling or cold rolling. This website follows CNS 2253 and lists JIS H4000 (Japanese Industrial Standards) as the corresponding reference standard. The English title of CNS 2253 is "Aluminium and aluminium alloy sheets, strips and plates." CNS 2253 is mainly for users in Taiwan. In other regions, please refer to the corresponding standard, such as JIS, GB (China), or EN (Europe).

Aluminum alloys are usually written as A plus four digits (for example A5052 or A6061), without the P at the end. If you ask for CNS 2253, the designation symbol is written with the P, as A5052P or A6061P. In the US, people often write AA 5052 or UNS A95052. In Europe, it is EN AW-5052.

As a rule, Sursun Metals does not add lead on purpose to the aluminum alloys we sell. Our SGS test reports show that our aluminum alloys meet RoHS (Restriction of Hazardous Substances). For exact composition, please use the mill test certificate (MTC) or a third-party test report.

The look of anodized aluminum may be affected by the alloy makeup, the rolling conditions, and the chemicals used in anodizing. Even the same alloy from different batches may show a color difference. If the look matters to you, we suggest using material from the same batch and doing a trial run first.

It is usually a white haze (also called water stain) that appears after the aluminum surface oxidizes. This cosmetic problem tends to happen when moisture gets trapped between layers of coil or sheet, when there is poor airflow, or when a change in temperature makes water form on the metal. We suggest storing aluminum in a dry place with good airflow. Keep water out of the coil or sheet stacks, and use the material soon after you open the package.