ASTM A500 Grade B


ASTM A500 Grade B

The ASTM A500 is a steel standard that covers cold-formed welded and seamless steel structural tubing in rounds and shapes. Grade B in the ASTM A500 standard is a steel grade that is used in construction, and it has a wide range of uses. It has a lower yield strength than Grade C, but a higher yield strength than Grade A. The most common application for steel tube Grade B is in construction, where it is used to create everything from tubular steel framing to steel beams. Steel tube Grade B is a versatile material that can be used in a variety of construction applications. Its strength and durability make it an ideal choice for structural elements such as steel framing, and its affordability makes it a popular choice for common construction applications.

Why choose tuspipe?


Since 1998, Tianjin United Steel Pipe Co., Ltd (TUSPIPE) has been committed to supplying high-quality line pipes.

With over 500,000 tons annual production capacity, the company serves various fields and industries, such as oil & gas exploitation and transmission, ship & auto-building, water & electricity, environmental protection, mechanical engineering, infrastructure construction and etc.

TUSPIPE places a premium on product quality and rigorous product quality control. In order to maintain good product quality,  the company has established a Test & Inspection Center since 2004. With a series of state-of-the-art tests and inspection equipment, the test & inspection center is able to perform the tensile tests, hydro tests, impact tests, DWTT, etc.

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ASTM A500 Grade B Square & Rectangle Tubing

The following are the three physical properties required for our ASTM A500 Grade B square, rectangular and special shape tubing. A flattening test is not a standard requirement for ASTM A500 Grade B non-circular tubes.

Grade Yield (min) Tensile (min) Elongation (min)
Gr. B 46,000 psi 58,000 psi Determined by wall

ASTM A500 Grade B Round Tubing

Below are the physical properties required to meet the three grades that we produce ASTM A500 Grade B round tubing.  A flattening test is also a standard requirement for round tubing produced to the ASTM A500 Grade B.

Grade Yield(min) Tensile (min) Elongation (min)
Gr. B 42,000 psi 58,000 psi Determined by wall

Chemical Requirements of ASTM A500 Grade B Pipes

Element Composition, %
Heat analysis Product analysis
Carbon 0.26 0.3
Manganese 1.35 1.4
Phosphorus 0.035 0.035
Sulfur 0.035 0.045
Copper 0.2 0.18

Physical Properties of ASTM A500 Grade B Pipes

Physical Properties Metric English Comments
Density 7.80 g/cc 0.282 lb/in³ Typical of ASTM Steel

Permissible Variations in Dimensions of ASTM A500 Grade B

-Outside Dimensions of ASTM A500 Grade B Pipes

ASTM A500 Grade B Round Structural Tubing

The outside diameter shall not deviate more than 60.5 percent, rounded to the nearest 0.005 in. [0.1 mm], from the specified outside diameter for specified outside diameters of 1.900 in. [48 mm] and smaller, and 60.75 percent, rounded to the nearest 0.005 in. [0.1 mm], from the specified outside diameter for specified outside diameters of 2.00in. [5 cm] and greater. Outside diameter measurements must be taken at least 2 in. [5 cm] from the tube ends.

ASTM A500 Grade B Square and Rectangular Structural Tubing

Outside dimensions, as measured across the flats at least 2in. [5cm] from the tube ends, should not deviate from the required outside dimensions by more than the amount provided, which includes an allowance for convexity or concavity.

- Wall Thickness of ASTM A500 Grade B Pipes

The minimum wall thickness of the ASTM A500 Grade B tube at any point of measurement should not be less than 10% of the stipulated wall thickness. The maximum wall thickness of welded tubing, excluding the weld seam, should not exceed 10% of the prescribed wall thickness.

The wall thickness standards for square and rectangular tubes must apply exclusively to the flats’ centers.

-Length of ASTM A500 Grade B Pipes

Structural tubing is often manufactured in random lengths of 5ft [1.5m] or more, multiple lengths, and specialized lengths. Section 4 should be consulted. When ordering particular lengths, the length tolerance must be in compliance.

-Straightness of ASTM A500 Grade B Pipes

The allowable deviation for ASTM A500 Grade B structural tube straightness must be 1/8in. times the number of feet [10 mm times the number of meters] divided by 5.

-Squareness of Sides of ASTM A500 Grade B Pipes

Adjacent sides of ASTM A500 Grade B square and rectangular structural tubes should be square (90°), with a maximum variation of 62° allowed.

-Radius of Corners of ASTM A500 Grade B Pipes

The radius of each outside corner of a square or rectangular structural tubing section should not be more than three times the required wall thickness.

-Twist of ASTM A500 Grade B Pipes

For ASTM A500 Grade B square and rectangular structural tubing, the permissible variations in twist shall be as given in the standard.Twist shall be determined by holding one end of the tubing down on a flat surface plate, measuring the height that each corner on the bottom side of the tubing extends above the surface plate near the opposite ends of the tubing, and calculating the twist (the difference in heights of such corners), with the exception that for heavier sections, a suitable measuring device may be used to determine twist. Twist measures must not be obtained within 2 in. [5cm] of the tubing’s ends.

ASTM A500 Grade B Product Marking of TUSPIPE

  • Each length of structural ASTM A500 GradeB tubing should be legibly marked with the following information: manufacturer’s name, brand, or trademark; specification designation (year of issuance is optional); and grade letter.
  • It is acceptable to indicate the information given in (1) on a tag firmly connected to each bundle for structural tubing with a defined outer diameter or big flat dimension of 4 in. [10 cm] or less.
  • Bar Coding—In addition to the standards in (1) and (2), the manufacturer must be able to use bar coding as an additional identifying technique. If a certain bar-coding system is stated in the purchase order, it must be used.

In the absence of any bar-coding method mentioned in the purchase order, bar coding should be compatible with AIAG Standard B-1.


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