The 1xxx Series and Purity Levels
The 1xxx series comprises commercial pure aluminum alloys containing at least 99 percent aluminum. 1050 has a minimum aluminum content of 99.50 percent and 1060 a minimum of 99.60 percent. The small difference in purity has a measurable effect on conductivity and formability: the higher the purity, the fewer impurity atoms interfere with the movement of electrons and dislocations. Both alloys are non-heat-treatable and are strengthened only by cold working, so their properties are controlled by the temper.
Electrical and Thermal Conductivity
Conductivity is the defining advantage of the 1xxx series. 1050 and 1060 achieve roughly 61 to 62 percent of the International Annealed Copper Standard for electrical conductivity, depending on temper and purity, with thermal conductivity in the region of 220 to 230 W per meter per kelvin. These values make them the standard choice for busbars, bus conductors, transformer strip and heat-exchange applications where efficient energy transfer matters more than strength.
Formability and Surface Quality
Pure aluminum is among the most formable metals. 1050 and 1060 coils bend, stamp, deep draw, spin and roll into very thin gauges without cracking, which is why they are used for lighting reflectors, kitchenware, nameplates and thin-gauge packaging. Their surface accepts bright polishing, brushing, anodizing and printing, and rolled coils can be supplied with controlled surface quality for decorative applications. Thickness tolerance and surface class are agreed with the mill and verified against the delivery specification.
Tempers and Coil Specification
Common tempers include O for maximum formability, H14 and H16 for a balance of strength and stiffness, and H18 for the hardest strain-hardened condition. Coils are specified by alloy, temper, thickness, width, inner diameter and weight. For processing lines, coil set and camber control are important, and for anodized or printed products the surface finish class must be defined in the order.
Applications
Typical uses of 1050 and 1060 coils include electrical conductors and busbars, transformer winding strip, heat exchanger fins, lighting reflectors, signage, food and household foil, bottle caps, kitchen utensils, architectural trim and general deep-drawn parts. The choice between the two grades is often driven by availability and by the specific conductivity or formability requirement of the product.
FAQ
Q: What is the difference between 1050 and 1060?
A: The difference is 0.1 percent in minimum aluminum content. 1060 has marginally higher conductivity and purity, while 1050 is more widely available and slightly stronger at the same temper. For most applications either grade performs equivalently.
Q: Can 1050 coils be anodized?
A: Yes. Pure aluminum anodizes to a bright, clear finish and is often chosen for reflective and architectural products specifically because the anodic film stays colorless.
Q: Is 1050 suitable for food contact?
A: Yes, high-purity aluminum is used for food and pharmaceutical foil and containers, provided the products meet the food-contact regulations of the destination market.
Q: Why is 1xxx series used for electrical applications instead of stronger alloys?
A: Because conductivity falls sharply when alloying elements are added. Where current-carrying capacity is the priority, the purity of the 1xxx series is worth more than the extra strength of alloyed grades.
Q: What temper is best for deep drawing?
A: The O temper gives maximum ductility and is the usual choice for severe deep-drawing operations. If a stiffer part is needed after forming, a strain-hardened temper can be selected with a slightly reduced draw ratio.