1. What is ASTM A500?
ASTM A500 is a standard specification published by ASTM International for cold-formed welded and seamless carbon steel structural tubing produced in round, square, rectangular, and special shapes-2. It is the most common specification for Hollow Structural Sections (HSS) used in construction in the United States-2-5.
2. What are the typical applications for A500 tubing?
This tubing is intended for welded, riveted, or bolted construction of bridges and buildings, and for general structural purposes-1-3-7. Common applications include building frames, bridges, towers, and various structural supports-5.
3. What are the size and thickness limits for A500 tubing?
The specification covers tubing with a maximum periphery (total outer perimeter) of 88 inches [2235 mm] and a maximum specified wall thickness of 1.000 inch [25.4 mm] according to the latest 2023 version-3. Older versions, like the 2018 edition, listed a maximum thickness of 0.875 in. [22 mm]-1-8. Domestically, square HSS is available up to 22x22 inches, rectangular up to 34 inches, and round up to 28 inches in diameter-5.
4. How is A500 tubing manufactured?
It is produced through a cold-forming process. The tubing can be either seamless or welded. Welded tubing is made from flat-rolled steel using the electric-resistance-welding (ERW) process, where the edges are heated and forged together-5-7.
5. What are the material grades under A500, and which is most common?
ASTM A500 defines several grades of carbon steel based primarily on material strength-2. Grade C, with a minimum yield strength of 50 ksi and tensile strength of 62 ksi, is the predominant material available for all shapes-5. Most domestically produced HSS is dual-certified for both Grades B and C, so Grade C is recommended as the default for project specifications-5.
