Q: When should I choose Q345 over Q235?
A: Choose Q345 when higher strength-to-weight ratio is needed, for high-pressure or high-stress applications, or where weight reduction is crucial.
Q: When is Q235 a more economical choice?
A: For non-critical, low-stress applications where strength is not the primary driver. It's generally cheaper per ton.
Q: Can Q235 and Q345 pipes be mixed in one structure?
A: Technically possible but requires careful design. They have different strength and stiffness; direct substitution is not allowed without recalculation. Welding them together needs special procedures.
Q: Which is better for galvanized pipes?
A: Both are extensively hot-dip galvanized. Q235 is very common for galvanized plumbing and structural pipes. Q345 is also galvanized for stronger structural needs.
Q: For piling pipes, which grade is used?
A: Q345 is predominant for large-diameter, thick-walled foundation piles due to its high strength and toughness requirements. Q235 may be used for minor, shallow foundations.
