What Are ASTM A500 Pipes?

This specification provides the methods for producing carbon steel piping of various types, including welding, cold-formed, and seamless. ASTM A500 piping is mostly used in construction and comes in shapes like round, rectangular, square, or customized sizing.

For this specification, processes like open hearth, electric, and basic oxygen furnaces are used to improve the mechanical properties of the steel. These steps improve its applications in construction projects like bridges, buildings, flyovers, and other large structures. 

Though ASTM A500 pipes come in grades A, B, C, and D, only the last one requires post-production heat treatments. 

Characteristic Features of ASTM A500 Pipes

  • Alongside round, rectangular, and square tubing, ASTM A500 also covers welded, bolted, and riveted tubing shapes for use in construction.
  • In comparison to ASTM A53 pipes, A500 piping has straightness tolerances of ¼” per every 10 feet, leading to better application in projects requiring curved structural steel. 
  • The Outer Diameter(OD) of A500 pipes range from 0.4 to 32.2 inches.
  • This specification states that A500 welded pipes must be made from electric resistance welding for optimum strength. The steel used must be flat-rolled, and the result must be unfurnished, still containing the flash. 
  • Grade B of ASTM A500 pipe has higher strength and closer tolerances fit for application in construction.
  • Longitudinal welding is preferred in welded pipes, especially one that uses butt joints that can be fused longitudinally to ensure the structural strength and design of the construction pipe.
  • ASTM A500 carbon steel pipes are to be made using open earth, electric, or basic oxygen furnace. 
  • Dimensional variations on wall thickness, Outside Diameter (OD), twist, and structural straightness are available during A500 pipe production. 

Dimensional Variations in ASTM A500 Pipes

Permissible Variations in Wall Thickness of ASTM A500 Pipes

According to ASTM A500 specifications, carbon steel pipes' wall thickness should not be less than 90% of the specified nominal wall thickness. Similarly, the maximum thickness should not exceed 110% of the given nominal wall thickness. However, variations within this 10% range are permitted below or above. This rule also excludes the fused seam region of welded pipes. 

The wall thickness should be taken at the flat center for shapes other than round, particularly rectangles and square-shaped pipes. This step is crucial as the WT for special-shaped pipes refers only to the inner center of the flats. 

Permissible Variation in Outside Diameter (OD) of ASTM A500 Pipes

A variation of 5% above or below the specified outer diameter is allowed in ASTM A500 pipes. However, for this to be applicable, the pipe must be round and have an outside diameter of 1.9 inches or smaller. 

For pipes that are rectangular or square-shaped, a similar variation is allowed. A maximum three-fold radius deviation from the specified wall thickness is authorized outside any corner of these pipes.

Variations in Straightness and Side Squareness of ASTM A500 Pipes

You can calculate the variation in pipe straightness using the following formula:

  • Permissible straightness of ASTM A500 carbon steel pipes = ⅛ inches X total pipe feet in length divided BY five.

Now, for square or rectangular structural tubing, a variation of 2 Degrees above the 90 degrees rule is permissible. 

Chemical Composition of ASTM A500 Pipes

  Element   ASTM A500 Grade A, Grade B, Grade D           ASTM A500 Grade C
   Heat Analysis  Product Analysis  Heat Analysis  Product Analysis
  Carbon  0.26% (max)  0.30% (max)  0.23% (max)  0.27% (max)
  Manganese  1.35% (max)  1.40% (max)  1.35% (max)  1.40% (max)
  Phosphorous  0.035% (max)  0.035% (max)  0.035% (max)  0.045% (max)
  Sulfur  0.035% (max)  0.045% (max)  0.035% (max)  0.045% (max)
  Copper  0.20% (min)  0.18% (min)  0.20% (min)  0.18% (min)

Tensile Properties of ASTM A500 Pipes (Shaped Structural Tubing)

                                           Shaped Structural Tubing
   Grade D  Grade C  Grade B  Grade A
  Elongation %(In 2 inches)  23% (min)  21% (min)  23% (min)    25% (min)
  Yield Strength  250 MPa (min)  345 MPa (min)  315 MPa (min)  270 MPa (min)
  Tensile Strength  400 MPa (min)  425 MPa (min)  400 MPa (min)  310 MPa (min)


What Are ASTM A 252 Pipes?

ASTM A252 covers the manufacturing standards of pile pipes, either seamless or welded. These pipes are available in Grades 1, 2, and 3, with the last one being mainly used in piling to help provide base stability and support to buildings and other construction projects. This specification includes nominal wall steel pipes with cylindrical shapes- to be used as permanent piles or casing for concrete piling.

For most standard construction jobs, ASTM A252 pipes of Grades 1 and 2, 3 should work just fine. Among these ASTM Grade-3, pipe piles are the preferred variety because they have a tensile strength of 60000 psi and yield strength of 45,000 psi. This specification covers only cylindrical-shaped pipes and excludes all rectangular steel pipes. 

Length Requirements for ASTM A252 Pipes

The specs for ASTM A252 pipes are as follows

  • Single Random Length (SRL)- 16 to 15 feet
  • Double Random Length (DRL)- Average of 35 ft, with a minimum length of 25 feet.
  • Uniform lengths under ASTM A252 should be as specified with an available variation of +/- 1 inch. 

Chemical Specifications for ASTM A252 Pipes

As for its mechanical properties, under ASTM A52 Specs, the maximum phosphorus content in piling pipes should not exceed 0.50%. This limit is necessary because this substance can make the steel brittle while adversely affecting the steel's welding capabilities. The other elements used in a pile should be administered according to the general requirements of carbon steel pipes. 

Tensile Measurements for ASTM A252 Grade 3 Pipes

GradeYield PointMin. Elongation at 2°Tensile StrengthMin. Elongation at 8° 
345000 psi20%66000 psi

Calculated Minimum Elongation Values of ASTM A252 Grade 3 Pipes

 Nominal Wall Thickness in Inches Minimum Elongation % in 2 Inches for ASTM A252 Grade 3
 5/16 or 0.312 inches 20.00
 9/32 or 0.281 inches 19.00
 ¼ or 0.250 inch 18.00
 7/32 or 0.219 inch 17.00
 3/16 or 0.188 inches 16.00
 11/64 or 0.172 inches 16.00
 5/32 or 0.156 inches 15.00
 9/64 or 0.141 inches 14.00
 1/8 or 0.125 inches 14.00
 7/64 or 0.109 inches 13.50

Types of Pipe Ends Permissable According to ASTM A252 Specifications

According to these standards; all pipes should have a standard plain end unless otherwise specified. Steel pipe piles should either possess machine-cut or flame-cut ends. Manufacturers must also remove the burrs at the ends of these pipes.

In cases where beveled edges are permissible, certain specifications must be maintained. According to ASTM A252 standards, all beveled-ended pipe piles must have an angle of 30 degrees +5, -0 degrees. These edges must be obtained by drawing a perpendicular line from the axis of the pipe pile.

Characteristic Features of ASTM A252 Pipes

  • Steel piles made according to ASTM A252 specifications can be seamless, electric resistance welded, flash, or fusion welded, longitudinal submerged arc welded, (LSAW), submerged helical arc welded (HSAW), or SSAW.
  • The seams of ASTM A252 welded piles should be helical-butt, helical-cap, or longitudinal.
  • ASTM A252 pipes are made using hot rolling, cold drawing,  open-hearth, basic oxygen, or electric furnace processes.
  • Grade 3 pipes made according to this specification have a higher tensile and yield strength of 455 Mpa and 310 MPa, respectively. This enhanced strength makes them a great fit for piling projects as they can weather the offensive driving force exerted by pile drivers onto the steel pipe piles.
  • When used in piling, ASTM pipe piles can be open or closed-ended, depending on the soil requirements. 
  • Unlike other specifications, a hydrostatic test is not required in ASTM A252 pipes. Since these pipes provide stability to project foundations, they are often filled with concrete instead of being used to transport liquids. This factor makes the test unnecessary in these steel pipe piles. 
  • However, these pipes must pass through a heat analysis and tests for tensile requirements and overall product quality before being considered fit for sale. 

Important Differences Between ASTM A252 Pipes and ASTM A500 Pipes

   ASTM A500 Pipes  ASTM A252 Pipes 
 This specification provides standards for carbon steel pipes used primarily in construction. They may be welded, bolted, and riveted tubing.  ASTM A 252 provides specifications primarily for piling pipes. It covers guides for seamless or welded pipes.
 Grades under this specification are marked as A, B, C, and D. The grades under this specification are marked as 1, 2, and 3.
These pipes are made using an open hearth, electric furnace, or basic oxygen heating. These pipes are generally made via hot rolling, cold drawing, open-hearth, or basic oxygen/electric furnaces.
 The butt ends should be longitudinal for these pipes to ensure strength and structural uniformity. The seams of ASTM A252 pipes must be a helical butt, helical cap or longitudinal.