1370 aluminum (UNS A91370) is a high-purity wrought aluminum alloy in the 1000 series, designated as Al99.7 by EN standards. With a minimum aluminum content of 99.7%, it is one of the highest-purity commercial aluminum grades used as electrical conductor (EC) material. The alloy is non-heat-treatable and gains strength through work hardening (strain hardening), primarily in H tempers. Its defining feature is electrical conductivity — approximately 61% IACS (International Annealed Copper Standard) in annealed condition — making it the material of choice for a wide range of electrical transmission and power distribution applications where high conductivity, light weight, and corrosion resistance are required. difference between 1350 and 1370 aluminum