ASTM A252 is the standard specification for seamless and welded steel pipes used as steel pipe piles. Grade 2 is the intermediate grade of ASTM A252, with a tensile strength of 415 MPa (60,000 psi) and a yield strength of 240 MPa (35,000 psi).
It is suitable for medium-load construction conditions, commonly applied in lighter load structures and favorable soil conditions, such as:
Small buildings
Temporary structures
Landscaping projects
Manufacturing Processes
ASTM A252 Grade 2 pipe piles can be produced using the following methods:
Seamless (SMLS)
Manufactured by hot rolling or cold drawing from a billet without welded seams.
Electric Resistance Welded (ERW)
Edges of steel plates are heated by resistive high-frequency current and welded under mechanical pressure.
Flash Welded
Edges are heated to a molten state and pressed together quickly.
Fusion Welded
Edges are heated to molten state and welded. Includes EFW, LSAW, and SSAW processes.
Seam Orientation:
Welded pipe piles can have longitudinal, helical-butt, or helical-lap seams.
Properly manufactured welded seams do not affect structural performance.
Chemical Composition
Phosphorus (P): ≤ 0.050%
A chemical analysis report shall be provided for each lot, even if not specifically requested in the order.
Mechanical Properties
ASTM A252 Grade 2 requires tensile testing as the primary mechanical assessment. Other tests such as flattening or bending are not mandatory under the standard.
Grade 2 Mechanical Summary
| Property | Minimum Value |
|---|---|
| Tensile Strength | 60,000 psi (415 MPa) |
| Yield Strength | 35,000 psi (240 MPa) |
| Elongation (8 in / 203.2 mm) | 14% |
| Elongation (2 in / 50.8 mm) | 20% |
Nominal Wall Thickness Adjustment:
For thicknesses below 5/16 in (7.9 mm), deduct from the basic 2 in elongation per 1/32 in (0.8 mm) decrease:
Deduction for Grade 2: 1.25% per 0.8 mm decrease
Minimum Elongation by Wall Thickness
| Nominal Wall Thickness | mm | Elongation in 2 in, min % |
|---|---|---|
| 5/16 (0.312) | 7.9 | 25.00 |
| 9/32 (0.281) | 7.1 | 23.75 |
| 1/4 (0.250) | 6.4 | 22.50 |
| 7/32 (0.219) | 5.6 | 21.25 |
| 3/16 (0.188) | 4.8 | 20.00 |
| 11/64 (0.172) | 4.4 | 19.50 |
| 5/32 (0.156) | 4.0 | 18.75 |
| 9/64 (0.141) | 3.6 | 18.25 |
| 1/8 (0.125) | 3.2 | 17.50 |
| 7/64 (0.109) | 2.8 | 16.75 |
Interpolation Formula:
For intermediate thickness:
E=1.56t+12.50E = 1.56t + 12.50E=1.56t+12.50
Where:
E = Elongation in 2 in (50.8 mm) %
t = Nominal wall thickness in inches (mm)
Certification
The manufacturer shall provide a Certificate of Compliance stating that all steel pipe piles:
Are manufactured, tested, and inspected in accordance with ASTM A252
Meet any additional requirements specified in the order
