What is the maximum fillet size along the edges of material for plates that are 6 mm thick or more?

• A. The thickness of the material
• B. The thickness of the material or 2 mm less than the thickness for materials 6 mm thick or more
• C. Twice the thickness
• D. Half the thickness

Answer: (B)

Sizing fillet welds along the edge of a plate follows the plate thickness. For plates that are 6 mm thick or more, the maximum leg length of a fillet weld along the edge is allowed up to the plate thickness, with a common constraint to use up to 2 mm less than the thickness in practice. This keeps the weld from becoming excessive relative to the material, helps control distortion, and supports reliable inspection. So for a plate 8 mm thick, a fillet up to 8 mm or 6 mm could be used depending on design; for 12 mm, up to 12 mm or 10 mm. The other options imply sizes that don’t reflect this thickness-based limit.