What welding processes are commonly used in structural steel fabrication?

• A. Welding is not used in structural steel.
• B. GMAW exclusively.
• C. SMAW, GTAW, FCAW, and GMAW depending on joint and quality requirements.
• D. SMAW, GTAW, and TIG only.

Answer: (D)

Structural steel fabrication relies on more than one welding process because different joint designs, thicknesses, and quality requirements demand different welding characteristics. SMAW (stick) is versatile and portable, well-suited for field work and a wide range of thicknesses. FCAW (flux-core) provides high deposition rates and performs well in shop or field environments, making it efficient for thicker joints. GMAW (MIG) is fast and easily automated, ideal for repetitive shop welds and fillet welds. GTAW (TIG) offers precise control and high-quality welds with clean finishes, though it is slower and typically used for critical joints or where appearance matters. Because of these trade-offs, the common practice is to use SMAW, FCAW, GMAW, and GTAW as needed, depending on joint design and quality requirements.