ASTM A500

ASTM A500 is a standard specification published by the ASTM for cold-formed welded and seamless carbon steel structural tubing in round, square, and rectangular shapes. It is commonly specified in the US for hollow structural sections, but the more stringent CSA G40.21 is preferred in Canada. Another related standard is ASTM A501, which is a hot-formed version of this A500. ASTM A500 defines four grades of carbon steel based primarily on material strength.^[1]

This is a standard set by the standards organization ASTM International, a voluntary standards development organization that sets technical standards for materials, products, systems, and services.

Density

Like other carbon steels, A500 and A501 steels have a specific gravity of approximately 7.85, and therefore a density of approximately 7850 kg/m³ (0.284 pounds per cubic inch).^[2]

Grades

A500 cold-formed tubing comes in four grades based on chemical composition, tensile strength, and heat treatment. The yield strength requirements are higher for square and rectangular than for round tubing. The minimum copper content is optional. Grade D must be heat treated.^[1]

Grade	UNS	Composition (% by weight in heat)					Minimum strength requirements
		C	Mn	P	S	Cu	tensile	yield (round)	yield (shaped)	elongation
		max %	max %	max %	max %	min %	MPa (ksi)	MPa (ksi)	MPa (ksi)	%
A	K03000	0.26	1.35	0.035	0.035	0.20	310 (45)	230 (33)	270 (39)	25
B	K03000	0.26	1.35	0.035	0.035	0.20	400 (58)	290 (42)	315 (46)	23
C	K02705	0.23	1.35	0.035	0.035	0.20	425 (62)	315 (46)	345 (50)	21
D	K03000	0.26	1.35	0.035	0.035	0.20	400 (58)	250 (36)	250 (36)	23

Mechanical Properties

Shaped structural tubing

Grade	Physical Properties		Mechanical Properties
	Density		Tensile Strength, Ultimate		Tensile Strength, Yield
	gram/ cubic cm	lb/cubic in	MPa	psi	MPa	psi
A	7.80	0.282	310	45000	270	39000
B		.305	400	58000	315	46000
C			425	62000	345	50000
D			400	58000	250	36000

References

1. ASTM A500/A500M-07.
2. A500A steel material properties Archived November 11, 2006, at the Wayback Machine, accessed October 8, 2006.