1. What is a key limitation of A500 noted in the standard?
The standard includes a cautionary note (Note 1) stating that products made to A500 "may not be suitable for those applications such as dynamically loaded elements in welded structures, etc., where low-temperature notch-toughness properties may be important"-1-3-6. This refers to the material's potential performance under impact or seismic loading at low temperatures, which is not guaranteed by the standard-6.
2. How does ASTM A500 differ from ASTM A1085?
While A500 is the prevalent standard, ASTM A1085 is an alternative that offers tighter dimensional tolerances, a maximum yield strength cap (70 ksi), and mandatory Charpy V-Notch (CVN) impact testing requirements (e.g., 25 ft-lb at 40°F)-5. This makes A1085 more efficient for design and suitable for demanding applications like primary bridge members, but it is typically produced on-demand and not as readily stocked as A500-5.
3. What is the relationship between ASTM A500 and ASTM A501?
ASTM A501 is the specification for hot-formed welded and seamless carbon steel structural tubing, making it the hot-formed counterpart to the cold-formed A500-2. However, it is noted that there are currently no domestic HSS producers manufacturing structural tubing to ASTM A501-5.
4. For larger sizes beyond typical A500 range, what specification is used?
For rectangular and square HSS with perimeters larger than 88 inches (up to 200 inches), ASTM A1065 is the applicable specification-5. These large sections are typically made by welding two cold-formed "C" shapes together using a submerged arc weld (SAW) process-5.
5. Is A500 suitable for corrosive environments without coating?
No, the standard A500 grade is not specifically formulated for corrosion resistance. For improved atmospheric corrosion resistance in applications where the steel might be left unpainted, ASTM A847 (a high-strength, low-alloy steel) is the appropriate HSS specification to specify-5.
