ASTM A992 is regarded as a replacement for A36 steel in a number of hot rolled steel structural applications.
The mechanical properties are not the same, though they're similar. A36 steel has minimum yield strength of 36ksi and an ultimate tensile strength of 58,000–80,000 psi.
Meanwhile, A992 has a tensile yield strength of 50 ksi (minimum) and an ultimate strength of 65 ksi (minimum). In other words, A992 has a higher minimum strength requirement. Elongation at break is about the same, 21% for pieces up to 2 inches thick, though ASTM A36 is a bit more ductile in thicker sections (up to 8 inches) at 20% vs. A992's 18%.
ASTM A36 and A992 are not chemically identical, though they're similar. A36 allows a hair more carbon minimum (0.25 to 0.29%) vs. 0.23% for A992, though A992 allows more carbon in certain situations.
A36 uses a bit less manganese (useful for controlling sulfur impurities), while A992 allows both more manganese and more sulfur. A992 should be a bit more weldable than A36, and emphasizes being a fully killed (deoxidized) steel while A36 leaves deoxidation open.
So, basically the two steels are close, even overlapping, and A992 has been used to replace A36 in a number of structural applications. But the differences warrant a closer look for specific applications.
