Products Description
ASTM A242 is a high-strength, low-alloy (HSLA) weathering steel, widely known as a type of COR-TEN® steel. When exposed to the atmosphere, it develops a protective, rust-like patina that eliminates the need for paint and shields the underlying steel from further corrosion. This self-protecting quality has made it a popular choice for outdoor architectural and structural applications since its introduction in 1958.
Key characteristics
Weathering mechanism: A242's composition, which includes alloys like copper, chromium, and phosphorus, allows it to form a stable, protective layer of iron oxide when exposed to wet and dry atmospheric cycles. This layer slows the corrosion process significantly.
Superior corrosion resistance: A242's atmospheric corrosion resistance is substantially better than that of conventional carbon steels like A36 and A572-50.
Aesthetic appeal: The steel's rich, rustic, and constantly evolving appearance makes it a favorite for architectural features, sculptures, and landscaping.
Primary applications
The durability and aesthetic properties of A242 weathering steel make it well-suited for a wide array of outdoor uses where reduced maintenance is desired.
Construction: Used for structural components in buildings, bridges, and other infrastructure projects.
Industrial structures: Common in smokestacks, industrial air ducts, and water tanks.
Transportation: Utilized for freight wagons, shipping containers, and railway cars.
Art and landscaping: Featured in sculptures and other outdoor aesthetic and landscaping installations.
Important considerations
Patina runoff: During the initial weathering process, A242 steel will produce rust-colored runoff that can stain adjacent surfaces like concrete. Measures should be taken to manage this runoff during installation.
Wet environments: While it is a weathering steel, A242 should not be used in conditions where moisture remains trapped and prevents the protective patina from fully drying and developing. This can lead to increased corrosion.
Thickness limitations: The A242 specification applies primarily to structural plates up to 4 inches (100 mm) thick, though its mechanical properties and typical applications vary with thickness.
COR-TEN® vs. A242: While often used interchangeably, COR-TEN® is the branded name originally registered by U.S. Steel. ASTM A242 is the standard specification for a weathering steel with similar properties.
Chemical Composition For Corten Steel ASTM A242 Type 1 Plate & Sheet
| Corten – A | ASTM 588 Grade A | ASTM 242 TYPE -1 | IRSM 41 -97 | |
| Carbon, Max | 0.12 | 0.19 | 0.15 | 0.10 |
| Manganese | 0.20-50 | 0.80-1.25 | 1.00 | 0.25-0.45 |
| Phosphorus | 0.07-0.15 | 0.04 | 0.15 | 0.07-0.11 |
| Sulphur, max | 0.030 | 0.05 | 0.05 | 0.030 |
| Silicon | 0.25-0.75 | 0.30-0.65 | 0.25-0.40 | 0.28-0.72 |
| Nickel, max | 0.65 | 0.40 | – | 0.20-0.49 |
| Chromium | 0.50-1.25 | 0.40-065 | – | 0.30-0.50 |
| Molybdenum, max | – | – | – | – |
| Copper | 0.25-0.55 | 0.25-0.40 | 0.20 min | 0.30-0.39 |
| Vanadium | – | 0.02-0.10 | – | 0.050 |
| Aluminimum | – | … | – | 0.030 |
Mechanical properties of corten steel ASTM A242 Type 1 plates & Sheets
| Tensile Strength | Min. Yield Point | Elongation | |
| CORTEN A | [470 – 630 MPa] | [355 MPa] | 20 % min |
| ASTM 588 GR. A | [485 MPa] | [345 MPa] | 21% min |
| ASTM 242 TYPE -1 | [480 MPa] | [345 MPa] | 16% min |
| IRSM 41- 97 | [480 MPa] | [340 MPa] | 21% min |
FAQ
What is an alternative to corten steel?
Mild Steel does not form a protective layer but aesthetically is very similar to Corten Steel. Corten starts to develop its trademark Patina quicker than Mild Steel. Mild Steel is a more cost-effective alternative to Corten for those budget-conscious gardeners.
Can I weld Corten steel?
When it comes to welding corten steel, the method should match the material thickness and end-use. Stick Welding (SMAW): Reliable and economical for structural joints. TIG Welding (GTAW): Clean and precise, suitable for fine applications.
How do you cut Corten steel?
Clamp the CORTEN Steel securely to the workbench. Start the metal saw and allow it to reach a steady operating speed. Slowly lower the saw blade onto the steel and cut along the marked line. Apply gentle, consistent pressure while cutting.
What is material code A242?
ASTM A242 material is a low alloy structural steel that has high strength. It comes with improved resistance to corrosion and high temperatures. ASTM A242 plate is usually supplied in normalized/ quenched and tempered condition. The ASTM A242 strips can be found in the Industrial air pollution stacks, water tanks, etc.
What is the ASTM A242 steel equivalent to?
The superior ASTM A242 steel properties allow this steel to be used in different applications. The ASTM A242 steel equivalent grade is bs-6323-5/6, JIS g3445, ASTM A214, ASTM A424 gr 1, din 17177, and EN 10217-1/2.
About Gnee
Founded in 2008, Gnee (Tianjin) Supply Chain Group Co., Ltd. specializes in the global trade and processing of Corten steel products.
• We handle all kinds of Corten engineering projects, such as bridges, gardens, hotels, and facade systems.
• Compliant with ASTM, EN, and other international standards; third-party inspection supported.
• Exported to over 200 countries and regions worldwide.
• 8 subsidiaries across China and overseas, ensuring global service coverage.
Application Fields: Architecture, landscaping, gardening, cladding, and urban infrastructure.
