1100-O Commercially Pure Aluminum: 99.0% Minimum Al

ASTM B209 · Updated: 2026-05-25

1100 is commercially pure aluminum (99.0% minimum Al) in the soft annealed (O) temper. It offers the highest thermal conductivity (222 W/m·K), electrical conductivity (59% IACS at O temper for EC grade), and corrosion resistance of all aluminum alloys—at the cost of very low mechanical strength. Used for chemical processing equipment, food processing, heat exchanger fins, electrical bus conductors, nameplates, and spun hollowware where formability and corrosion resistance matter more than strength. Work-hardens slowly, enabling deep drawing and complex spinning operations without intermediate annealing.

Quick Facts

CategoryAluminum Alloy
StandardASTM B209
Density2.71 g/cm³
Yield Strength34 MPa (5 ksi) annealed
Tensile Strength90 MPa (13 ksi) annealed

Global Equivalents & Cross-Reference

Alternative Standard / GradeAction
EN AW-1100 Compare
Al99.0Cu Compare
A1100 Compare
AA1100-O Compare
ISO Al99.0Cu Compare

Related Materials

🧮 Material Weight Calculator

Calculate the weight based on this material's density: 2.71 g/cm³

Frequently Asked Questions

What is the difference between 1100 and 1350 aluminum?

1350 (formerly EC grade) is specifically refined for electrical conductor applications with 99.50% minimum Al and controlled impurities to achieve minimum 61.0% IACS conductivity. 1100 is a general-purpose grade with 99.0% minimum Al and slightly lower conductivity (~59% IACS) but better formability and wider availability. For bus bars, use 6101-T6 (heat-treated for strength + conductivity).