Q235B (China GB standard) is approximately equivalent to ASTM A36 (USA), EN S235JR (Europe), JIS SS400 (Japan), and DIN St37-2 (Germany). All have minimum yield strength around 235–250 MPa and tensile strength 370–500 MPa. Note that exact chemical composition limits may differ slightly between standards. Q235B and A36 are the most widely compared structural steel grades globally.

Q345B steel is approximately equivalent to ASTM A572 Grade 50 and EN S355JR. All have minimum yield strength of 345–355 MPa. Japanese equivalent is SM490. Q345B is one of the most widely used low-alloy structural steels in China for bridges, buildings, and heavy machinery. The "B" suffix indicates impact test at 20°C; Q345C/D/E are for lower temperature impact requirements.

304 (18Cr-8Ni) is the most common austenitic grade, suitable for general corrosion resistance. 316 (16Cr-10Ni-2Mo) contains 2–3% molybdenum, providing superior resistance to pitting and crevice corrosion, especially in chloride/salt environments. 316 is preferred for marine, chemical, pharmaceutical, and coastal applications. 316 is typically 30–50% more expensive than 304. Both grades are available in "L" variants (304L, 316L) with lower carbon content for better weldability.

DX51D+Z is a European EN 10346 designation. "DX51D" indicates the base steel grade suitable for forming, and "+Z" means hot-dip zinc coated (galvanized). The equivalent is ASTM A653 CS-B (USA), JIS SGCC (Japan), and GB DC51D+Z (China). It is the most commonly used commercial quality galvanized steel for general forming, roofing, and light construction applications.

No. Grade equivalents are approximate cross-references based on similar chemical composition and mechanical properties. Exact specifications may differ in: chemical element limits, impact test temperatures, testing methods, tolerances, and delivery conditions. For example, Q345B and A572 Gr.50 have similar yield strength but slightly different chemistry requirements. Always consult the actual standard document and confirm with your engineer or inspection agency before substituting one grade for another in critical applications.