ASTM A 500 Grade A, B and D for Tubing in Rounds and Shapes
ASTM A500 Grade A, B and D Standard Specification for Cold-Formed Welded and Seamless Carbon Steel Structural Tubing in Rounds and Shapes
This specification covers cold-formed welded and seamless carbon steel round, square, rectangular, or special shape structural tubing for welded, riveted, or bolted construction of bridges and buildings, and for general structural purposes.
Chemical Requirement
Chemical composition — Cast analysis for product thickness ≤ 40 mm
A For each reduction of 0.01 percentage point below the specified maximum for carbon, an increase of 0.06 percentage point above the specified maximum for manganese is
permitted, up to a maximum of 1.50 % by heat analysis and 1.60 % by product analysis.
B If copper-containing steel is specified in the purchase order
- Applies to specified wall thicknesses (t ) equal to or greater than 0.120 in. [3.05 mm]. For lighter specified wall thicknesses, the minimum elongation values shall be calculated by the formula: percent elongation in 2 in. [50 mm] = 56t + 17.5, rounded to the nearest percent.
- Applies to specified wall thicknesses (t ) equal to or greater than 0.180 in. [4.57 mm]. For lighter specified wall thicknesses, the minimum elongation values shall be calculated by the formula: percent elongation in 2 in. [50 mm] = 61t + 12, rounded to the nearest percent.
- Applies to specified wall thicknesses (t ) equal to or greater than 0.120 in. [3.05 mm]. For lighter specified wall thicknesses, the minimum elongation values shall
be by agreement with the manufacturer. - The minimum elongation values specified apply only to tests performed prior to shipment of the tubing.
Permissible Variations in Dimensions
1. Outside Dimensions:
Round Structural Tubing—The outside diameter shall not vary more than 60.5 %, rounded to the nearest 0.005 in. [0.1 mm], from the specified outside diameter for specified outside diameters 1.900 in. [48 mm] and smaller, and 6 0.75 %, rounded to the nearest 0.005 in. [0.1 mm], from thespecified outside diameter for specified outside diameters 2.00 in. [5 cm] and larger. The outside diameter measurements shall be made at positions at least 2 in.[5 cm] from the ends of the tubing.
Square and Rectangular Structural Tubing—The outside dimensions,measured across the flats at positions at least 2 in. [5 cm] from the ends of the tubing, shall not vary from the specified outside dimensions by more than the applicable amount given in Table 3, which includes an allowance for convexity or concavity.
Wall Thickness—The minimum wall thickness at any point of measurement on the tubing shall be not more than 10 % less than the specified wall thickness. The maximum wall thickness, excluding the weld seam of welded tubing, shall be not more than 10 % greater than the specified wall thickness.For square and rectangular tubing, the wall thickness requirements shall apply only to the centers of the flats.
Length—Structural tubing is normally produced in random lengths 5 ft [1.5 m] and over, in multiple lengths, and in specific lengths. When specific lengths are ordered, the length tolerance shall be in accordance with the below table
Straightness—The permissible variation for straightness of structural tubing shall be 1⁄8 in. times the number of feet [10 mm times the number of metres] of total length divided by 5.
Squareness of Sides—For square and rectangular structural tubing, adjacent sides shall be square (90°), with a permissible variation of 62° max.
Radius of Corners—For square and rectangular structural tubing, the radius of each outside corner of the section shall not exceed three times the specified wall thickness.
Twist—For square and rectangular structural tubing,the permissible variations in twist shall be as given in below Table. 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), except that for heavier sections it shall be permissible to use a suitable measuring device to
determine twist. Twist measurements shall not be taken within 2 in. [5 cm] of the ends of the tubing.
Length Tolerances for Specific Lengths of Structural Tubing
Permissible Variations in Twist for Square and Rectangular Structural Tubing
