Structural fabrication practice: Which weld type is the most common connection used in structural steel fabrication and detailing?

Introduction / Context:
Steel structures rely on standardized weld types for connections between plates, angles, and tees. Recognizing the most commonly specified weld in shop drawings and erection details is essential for reading and producing fabrication documents.

Given Data / Assumptions:

• Typical building and bridge steel fabrication per common codes.
• Connections include lap joints, T-joints, and corner joints.
• Focus on frequency of use and practicality.

Concept / Approach:
Fillet welds are triangular welds placed in the corner of lap, T-, and corner joints. They are easy to produce, require less edge preparation than groove welds, and accommodate a wide range of connection geometries. Because of versatility and economy, fillet welds dominate everyday structural connections, such as angle clip-to-web or plate-to-stiffener details.

Step-by-Step Solution:

Verification / Alternative check:
Review standard connection libraries from typical steel manuals—fillet weld callouts appear most often for secondary and many primary connections.

Why Other Options Are Wrong:

• Beam weld: Not a weld type; beams are members that may be welded with various weld types.
• Rivet weld: Mixing historical fasteners (rivets) with welding; not a recognized weld category.
• Structural weld: Vague description; does not specify a weld geometry or process.

Common Pitfalls:
Assuming full penetration groove welds are always preferred; while critical in some moment connections, they are less common overall than fillet welds.

Final Answer:
Fillet weld