The ASTM A252 standard covers steel piling pipe that is used in the construction industry for foundation applications. The ASTM A252 steel piling pipe is available in three grades based on strength levels: Gr.1, Gr.2, and Gr.3.
The A252 steel piling pipe is made to requirements that include chemical composition, mechanical properties, and dimensions. The A252 steel piling pipe can be ordered in both welded and seamless steel construction, and each type has its own advantages. Welded steel pipe offers a lower cost option for foundations, while seamless steel pipe provides a higher degree of strength and durability. ASTM A252 Grade 1 and Grade 2 steel piling pipe are suitable for most foundation applications, while Grade 3 steel pipe can be used for high-strength applications.
Steel Grades of ASTM A252 Steel Piling Pipe
Based on the tensile strength and the yield strength the ASTM A252 is classified into three categories/grades: ASTM A252 Grade1/ ASTM A252 Grade2/ ASTM A252 Grade3, each standard has its own application scenarios, the most commonly used of which is the Grade2 standard, to learn more about each pipe, you can click on the product links below!
ASTM A252 Grade 1
ASTM A252 Grade 1 steel pipe pertains to pipe piles with a nominal (average) wall steel cylinder serving as a permanent load-carrying element or as a shell to build case-in-place concrete piles
ASTM A252 Grade 2
ASTM A252 Grade 2 steel pipe is one of the most commonly used pile pipes. Because of their tremendous strength, they are thought to be employed in applications that need strong structural qualities.
ASTM A252 Grade 3
ASTM A 252 Grade 3 has the highest mechanical properties, with better strength and corrosion resistance. Usually used for higher pressure and more important projects, such as large bridges, docks, harbors, etc.
Specification of ASTM A252
| Standard | A252 |
| Specification | Welded Steel Pipe Piles |
| Type | Electric Resistance Welded (ERW) |
| Size | NPS 1 TO NPS 24 [DN25 to DN 600], with nominal average wall thickness as given in ASME B 36.10M or as the customer's requirement. |
| Outer Diameter | 1-24 inches (33.4-609.6mm) |
| Thickness | 3-12mm |
| Length | Min 3 M, Max18 M, or according to the customer's requirement. |
| Ends | Small sizes are plain, large sizes are beveled, or according to the customer's requirement |
| Surface Treatment | Normally bare or black varnish |
| Packaging | Small sizes below 219.1mm in bundles, large sizes in bulk |
| Testing | Chemical Composition, Heat Analysis, Product Analysis, Tensile Requirements, etc. as customer's requirements. |
Chemical Composition of ASTM A252 Steel Piling Pipe
The chemical analysis is quite important when ordering ASTM A252 steel pipes. The chemical analysis shall be performed by test methods, practices, and terminology ASTM A751.
It shall be permissible for the buyer to make product analyses using 2 samples from each heat lot of pipe piles. The chemical composition thus determined shall conform to the requirement specified for phosphorus. The steel shall contain no more than 0.050% phosphorous.
Mechanical Properties of ASTM A252 Grade 2/GRADE 3/GRADE
The ASTM A252 pipes must obey the demands for tensile properties that are set out in the tables below. The yield point is the point at which the beam falls, as detected by the gauge of the testing machine, dividers, or other accepted methods. If there is no definite yield point apparent, then the yield strength corresponding to either a 0.2% permanent offset of the gage length specimen or a 0.5% total extension of the gage length under load shall be determined instead. In other words, the material must meet certain standards for tension and yield to be viable for use. This is to ensure that it will not break under stress or strain and cause injury.
- Tensile Requirements
| Item | ASTM A252 Grade 1 | ASTM A252 Grade 2 | ASTM A252 Grade 2 |
|---|---|---|---|
| Tensile strength, min, psi (MPa) | 50000 (345) | 60000 (415) | 66000 (455) |
| Yield point or yield strength, min, psi (MPa) | 30000 (205) | 35000 (240) | 45000 (310) |
- Minimum Elongations
| Nominal Wall Thickness | Elongation in 2 in. (50.8 mm), min, % | |||
|---|---|---|---|---|
| in. | mm | AATM A252 Grade 1 | ASTM A252 Grade 2 | ASTM A252 Grade 3 |
| 5⁄1 6 or 0.312 | 7.9 | 30 | 25 | 20 |
| 9⁄32 or 0.281 | 7.1 | 28.5 | 23.75 | 19 |
| 1⁄4 or 0.250 | 6.4 | 27 | 22.5 | 18 |
| 7⁄32 or 0.219 | 5.6 | 25.5 | 21.25 | 17 |
| 3⁄1 6 or 0.188 | 4.8 | 24 | 20 | 16 |
| 11⁄64 or 0.172 | 4.4 | 23.25 | 19.5 | 15.5 |
| 5⁄32 or 0.156 | 4 | 22.5 | 18.75 | 15 |
| 9⁄64 or 0.141 | 3.6 | 21.75 | 18.25 | 14.5 |
| 1⁄8 or 0.125 | 3.2 | 21 | 17.5 | 14 |
| 7⁄64 or 0.109 | 2.8 | 20.25 | 16.75 | 13.5 |
Permissible Variations of ASTM A252
| Item | Tolerance |
|---|---|
| Unit Weight | +15%,-5% |
| Outside Diameter | ±1% |
| Wall Thickness | ±12.5% |
The ASTM A252 standard specifies that each length of pipe pile must be weighted separately, and the weight must not vary more than 15% over or 5% under the theoretical weight. This ensures that the pipe will be able to support the load that it is intended to bear.
The outside diameter of pipe piles shall not deviate from the required outside diameter by more than 1%.
At no point shall the wall thickness deviate by more than 12.5% below the nominal wall thickness.
Applications of ASTM A252
Nowadays, ASTM A252 pipe piling is being developed for use in a direction with deep distances and large diameters, since structures, buildings, and bridges are becoming increasingly tall, even super tall.
Piling pipe has a cylindrical design that bears weight and is suitable for a wide range of applications, including Buildings, Retaining walls, and Different structures that need a tough base. This guarantees that the construction is solid, stable, and of the greatest quality, ensuring toughness that satisfies international quality standards. The large diameter of the pipe prevents it from breaking under the weight of the structure or building. The pipe is also essential in stabilizing the foundation of the Retaining wall.
Different structures need a tough base material that can resist different types of loads without bending or breaking. In conclusion, piling pipes have a large variety of applications due to their durability and strength.
ASTM A252 Welded Pipe Test Requirements
Tension test: At the option of the manufacturer, the tension test specimens shall be longitudinal or transverse strip test specimens, with a gage length of 2 in.
Heat Analysis: Limits to elements P, and heat result shall be reported in MTC to customer.
Hydrostatic test : Hydrotest is not required
Outside Diameter: The outside diameter of pipe piles shall not vary more than 61 % from the specified outside diameter.
Surface imperfections: Having a depth not in excess of 12.5 % of the specified nominal wall thickness shall be acceptable. It shall be permissible to establish the depth of such
imperfections by grinding or filing.
