Coils

Weathering Steel Coil — ASTM A606 Type 4

CortenUSA sources and supplies cold-rolled weathering steel coil to the exact specification the metal roofing and architectural markets demand — ASTM A606 Type 4, the standard that defines true Corten performance.

A606 Type 4 is not a coated steel. It is not painted. It is a high-strength, low-alloy steel engineered at the molecular level to form a tightly bonded oxide layer — a living patina that seals the surface, arrests corrosion, and deepens in character over time. No maintenance. No touch-up. No apology.

Our coil is cold rolled to tight thickness tolerances, processed to a light oil finish, and wound on a 20″ inside diameter standard for direct compatibility with modern rollforming and coil processing equipment. Available in 24 GA and 22 GA, in master widths of 44″ and 48″, with slit-to-width capability for any finished panel width your operation requires.

Specification at a Glance

• Standard: ASTM A606 Type 4
• Process: Cold rolled
• Gauge: 24 GA / 22 GA
• Width: 44″ and 48″ master coil — slit to width available
• Inside diameter: 20″ standard
• Surface: Light oil
• Tolerances: Squareness and flatness processed per ASTM specifications
• Documentation: Mill test report available upon request

Whether you are running standing seam, corrugated, PBR, or Gulf Coast profiles — this is the coil built to run clean, coil tight, and weather beautifully for the life of the structure.