ASTM A252 Grade 3 is the most widely utilized material for cylindrical pipe piles.
Grade 3 steel pipe piles are not restricted to a single manufacturing route and can be produced through multiple pipe-forming technologies, such as SMLS (seamless), SAW (submerged arc welded), and EFW (electro-fusion welded). This versatility enables it to accommodate a broad range of engineering requirements and construction conditions.
As the highest-rated grade within the A252 specification, it delivers superior mechanical performance, featuring a minimum yield strength of 310 MPa and a minimum tensile strength of 455 MPa. It can function as a permanent load-bearing structural element or serve as a casing for cast-in-place concrete piles.
Dimension Range
The company has adopted a full set of advanced Gnee LSAW steel pipe production lines and testing systems, focusing on the manufacture of thick-wall, large-diameter LSAW steel pipes using DSAW (double-sided submerged arc welding).
The product range includes:
Outer Diameter: DN 350 – 1500;
Wall Thickness: 8 – 80 mm;
Pipe End
Pipe piles are supplied with plain ends.
Ends shall be flame-cut or machine-cut and properly deburred.
For beveled ends, the bevel angle should be within 30 – 35°.
ASTM A252 Grade
The ASTM A252 specification classifies steel pipe piles into three grades to accommodate different service conditions and loading criteria. The three grades are:
Grade 1, Grade 2, and Grade 3.
Manufacturing Process of ASTM A252
A252 steel pipes may be produced using seamless, electric resistance welded, flash welded, or fusion welded processes.
Weld seams on pipe piles may be longitudinal, spiral-butt, or spiral-lap.
Selecting the correct manufacturing process is essential for ensuring the quality and performance of steel pipe piles.
The LSAW (SAWL) method is particularly suitable for large-diameter, heavy-wall pipe, especially in construction and infrastructure applications requiring high load-bearing capability and deep foundation support. With its superior strength, load-capacity, and adaptability to varying geological conditions, it offers advantages such as fast installation and long-term structural reliability.
Chemical Components of ASTM A252 Grade 3
The steel shall contain no more than 0.050% phosphorus.
This phosphorus limitation ensures the steel maintains favorable mechanical properties, particularly for structural applications like piling.
Restricting phosphorus prevents excessive brittleness at low temperatures, thereby improving safety and reliability.
No specific requirements are provided for other alloying elements.
This is because pipe piles primarily emphasize structural strength and toughness-key attributes for supporting load-bearing structures.
Mechanical Performance of ASTM A252 Grade 3
For tubular piling, mechanical characteristics such as yield strength, tensile strength, and toughness are prioritized because they directly influence load-bearing capacity and overall structural stability during service.
Applications for ASTM A252 Grade 3 Steel Tubing
ASTM A252 Grade 3 offers high strength and toughness suitable for various soil conditions and load-bearing scenarios. Common applications include:
Building foundations: ASTM A252 Grade 3 steel pipe is widely applied as foundation piles in the construction of high-rise buildings, bridges, and major structures, providing essential strength and rigidity.
Ports and harbors: These steel piles are used in marine engineering to support docks and wharves, ensuring resistance to vessel impact and marine corrosion. Protective coatings are often applied to enhance durability and anti-corrosion performance.
Waterworks: ASTM A252 Grade 3 pipes are employed in dams, levees, lock systems, and other hydraulic projects to reinforce riverbanks and improve flood protection.
Energy projects: In wind farms, offshore platforms, and various energy-related facilities, these pipes act as structural supports to ensure stable operation.
Transportation facilities: ASTM A252 Grade 3 steel pipes are used for piling in railways, highways, and airport runways, providing strong load-bearing capability and long-term durability.
