Products Description
ASTM A847 is a weathering steel, classified as a high-strength low-alloy material, suitable for cold-formed welded square and rectangular tubing and pipe. Its resistance to atmospheric corrosion in most environments is significantly superior to that of standard carbon steel, whether or not copper is added.
ASTM A847 is designed for welded, bolted, or riveted construction of bridges and other structures that demand both high strength and enhanced corrosion resistance. The material provides a minimum yield strength of 50 ksi (approximately 345 MPa) and a minimum tensile strength of 70 ksi (approximately 485 MPa).
The tubing is cold-formed and welded to ensure chemical uniformity across the entire surface, with no additional metal introduced during the welding process. The cold-forming technique improves physical properties, maintaining the minimum yield and tensile strength of 50 ksi and 70 ksi, respectively.
This specification is tailored for structural applications where weight reduction and superior corrosion resistance are critical. ASTM A847 is particularly suited for welded and bolted structures, making it the preferred choice whenever high strength and enhanced durability against corrosion are required.
Due to its ability to develop a stable oxide layer on the surface, ASTM A847 tubing is commonly referred to as "weathering steel," providing natural protection against atmospheric corrosion. In terms of corrosion resistance and weathering performance, it is comparable to ASTM A588 and ASTM A606 Type 4 steels.
Key Features and Benefits of ASTM A847 Steel Tubing
Enhanced Atmospheric Corrosion Resistance: ASTM A847 steel tubing contains copper (0.25–0.55%), chromium (0.30–1.00%), nickel (≤0.40%), and phosphorus (≤0.035%), providing significantly better corrosion resistance than standard carbon steel. This makes it ideal for bridges, buildings, and other outdoor structures exposed to harsh environmental conditions. Its weathering properties allow it to resist atmospheric corrosion and pitting over extended periods, extending the service life of the structure.
High Strength and Durability: ASTM A847 weathering steel tubing offers a minimum yield strength of 50 ksi (approximately 345 MPa) and a minimum tensile strength of 70 ksi (approximately 485 MPa), ensuring excellent structural integrity and load-bearing capability. It is capable of withstanding heavy loads and dynamic forces, making it suitable for a wide range of applications where strength and durability are critical.
Cost-Effective and Low Maintenance: The corrosion-resistant properties of ASTM A847 steel tubing eliminate the need for additional protective coatings, reducing maintenance requirements and overall lifecycle costs. This makes it a cost-effective choice for long-lasting structures with minimal upkeep.
Aesthetic Appeal: Like other weathering steels, ASTM A847 develops a distinctive rusted appearance over time. Its warm tones and textured surface enhance the visual appeal of architectural and artistic applications, while maintaining an attractive appearance outdoors without the need for coatings.
Chemical Requirements
| Element | Heat Analysis |
| Carbon % | 0.20 max |
| Manganese | 1.35 max |
| Phosphorous % | 0.04 max |
| Sulphur | 0.035 max |
| Copper % | 0.20 min (if chromium & silicon are each .050 minimum, copper min does not apply) |
Physical Requirements
| Test | Strength |
| Yield | 50,000 psi |
| Tensile | 70,000 psi |
| Elongation | 19% (Applies to wall thicknesses 0.120 and over. For lighter wall thicknesses, elongation will be by agreement.) |
Applications of ASTM A847 Steel Tubing
Structural Components: ASTM A847 steel tubing is widely used in structural components such as bridges, buildings, and transmission towers. Its high strength, corrosion resistance, and lightweight properties make it a preferred choice for these critical structural applications, ensuring long-lasting durability and structural integrity.
Architectural and Construction Applications: The unique weathered appearance of ASTM A847 steel tubing adds a visually appealing element to architectural projects. It is commonly utilized for facades, roofing systems, cladding, and other design elements that require both durability and aesthetic appeal. The weathering process not only enhances its visual appeal but also provides additional protection against corrosion, making it suitable for exterior architectural features.
Outdoor Furniture and Sculptures: The corrosion-resistant nature and weathered appearance of ASTM A847 steel tubing make it ideal for outdoor furniture, art installations, and sculptures. Its ability to withstand environmental conditions ensures the longevity and beauty of such pieces, making it a popular choice among designers and artists for creating outdoor structures and artworks that stand the test of time.
