A500 CARBON AND ALLOY STEEL PIPE, ELECTRIC FUSION WELDED STEEL PIPE

American Piping Products stocks A500 cold-formed welded and seamless carbon steel structural tubing in grades A, B, C and D.

Scope

This specification covers cold-formed welded and seamless carbon steel round, square, rectangular or special shape structural tubing for construction of bridges, buildings and for structural purposes.

Process

The steel is produced by one or more of the following processes: Open hearth, basic oxygen or electric furnace.

Chemical requirements

ElementComposition, %
Grades A, B and DGrade C
Heat analysisProduct analysisHeat analysisProduct analysis
Carbon, maxA 0.260.300.23 0.27
Manganese, maxA 1.351.401.351.40
Phosphorus, max 0.0350.0350.0350.045
Sulfur, max 0.0350.0450.0350.045
Copper, minB 0.200.180.200.18
AFor 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.
BIf copper-containing steel is specified in the purchase order.

Heat treatment

Only grade D requires heat treatment.

Tensile requirements

Round structural tubing
Grade AGrade BGrade CGrade D
Tensile strength, min, psi (MPa)45,000 (310)58,000 (400)62,000 (425)58,000 (400)
Yield strength, min, psi, (MPa)33,000 (230)42,000 (290)46,000 (315)36,000 (250)
Elongation in 2 in. (50 mm), min, %D25A23B21C23B
Shaped structural tubing
 Grade AGrade BGrade CGrade D
 Tensile strength, min, psi (MPa) 45,000 (310) 58,000 (400) 62,000 (425) 58,000 (400)
 Yield strength, min, psi, (MPa) 39,000 (270)46,000 (315)50,000 (345)36,000 (250)
 Elongation in 2 in. (50 mm), min, %D 25A 23B 21C 23B

 AApplies 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. (50mm) = 56t + 17.5, rounded to the nearest percent. For A500M use the following formula: 2.2t + 17.5, rounded to the nearest percent.

BApplies 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. For A500M use the following formula: 2.4t + 12, rounded to the nearest percent.

CApplies 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.

DThe minimum elongation values specified apply only to tests performed prior to shipment of the tubing.

Permissible variations in wall thickness

The minimum wall thickness on tubing must not be more than 10% less than the specified wall thickness. The maximum wall thickness must not be more than 10% greater than the specified wall thickness (excluding the weld seam of welded tubing). The wall thickness for square and rectangular tubing only applies to the centers of the flats.

Permissible variations in outside diameter

For round structural tubing with outside diameters of 1.900” and smaller: Outside diameter shall not vary more than +/- 5% from specified outside diameter.

For square and rectangular tubing, see the chart below:

Specified outside large flat dimension, in. (mm)Permissible variations over and under specified outside flat dimensionsA, in. (mm)
2.5 (65) or under0.020 (0.5)
Over 2.5 to 3.5 (65 to 90), incl0.025 (0.6)
Over 3.5 to 5.5 (90 to 140), incl0.030 (0.8)
Over 5.5 (140)0.01 times large flat dimension
AThe permissible variations include allowances for convexity and concavity. For rectangular tubing having a ratio of outside large to small flat dimension less than 1.5, and for square tubing, the permissible variations in small flat dimension shall be identical to the permissible variations in large flat dimension. For rectangular tubing having a ratio of outside large to small flat dimension in the range of 1.5 to 3.0 inclusive, the permissible variations in small flat dimension shall be 1.5 times the permissible variations in large flat dimension. For rectangular tubing having a ratio of outside large to small flat dimension greater than 3.0, the permissive variations in small flat dimension shall be 2.0 times the permissible variations in large flat dimension.

Reference documents

ASTM A370 Test Methods and Definitions for Mechanical Testing of Steel  Products
ASTM A700 Practices for Packaging, Marking and Loading Methods for Steel Products for Shipment
ASTM A751 Test Methods, Practices and Terminology for Chemical Analysis of Steel Products
ASTM A941 Terminology Relating to Steel, Stainless Steel, Related Alloys and Ferroalloys