RUSTIC APPEARANCE EXPOSED FASTENED Material Description Weathering Steel is known as High-Strength, Low-Alloy, Cold-Rolled, with Improved Atmospheric Corrosion Resistance, per ASTM A 606-18, Type 4. Weathering Steel is produced by steel mills under trade names of Corten, Kupten, Triacor and others. Weathering Steel develops a pleasing iron oxide