1350

1350 (formerly known as "EC" — Electrical Conductor) is a 1xxx-series aluminum alloy with a minimum of 99.50% aluminum and strict impurity limits. It is the reference alloy for electrical conductors because it offers the highest conductivity of all extruded aluminum alloys. It is used in electrical power distribution (high/medium-voltage conductors, bus bars, cable sheathing), electronics (foils, heat sinks and heat spreaders), and telecommunications (overhead transmission lines).

1350 reaches an electrical conductivity of 61–62% IACS, the highest of all extruded aluminum alloys, and a thermal conductivity of 230 W/m·K. These values are a direct result of its purity (≥99.50% Al) and impurity limits specifically engineered to maximize electrical performance.

Because nearly any element in solid solution degrades the electrical conductivity of aluminum. That is why 1350 limits copper to ≤0.05%, silicon to ≤0.10%, iron to ≤0.40%, zinc to ≤0.05%, and keeps manganese and chromium at ≤0.01% each. Elements like Mn, Cr, V, and Ti are kept extremely low precisely because they degrade electrical performance.

No. 1350, like all 1xxx-series alloys, is non-heat-treatable; its strength is increased exclusively through cold work (work-hardening). In the annealed condition (O temper) it has low strength and high ductility (23–35% elongation, ~23 HB hardness), while cold working can raise tensile strength up to the 83–186 MPa range.

Thanks to its high purity, 1350 is very ductile and easy to form, extrude, and draw, making it ideal for cables and conductors. Pure 1xxx-series aluminum alloys offer excellent corrosion resistance and good weldability. The trade-off is low mechanical strength, so it is selected for its electrical and conductivity properties rather than structural strength.

1350 is designated as follows across the major systems: AA (USA) 1350 (EC); EN (Europe) EN AW-1350 · EAl99.5; DIN (Germany) E-Al99.5 / 3.0257; and ISO EAl99.5. The old name "EC" comes from "Electrical Conductor."