Which of the following is an acceptance criterion for a fillet weld in structural steel per typical codes?

• A. No cracks in the weld.
• B. The weld must be perfectly flat with no finish requirement.
• C. The weld size must exceed the specified throat by a large margin.
• D. The base metal must be completely melted.

Answer: (A)

Cracks in the weld signal a fundamental defect that codes treat as unacceptable for structural integrity. The ability of a fillet weld to carry load depends on a sound fusion without cracks; even small cracks can propagate under service stresses and lead to failure, so the presence of cracks is a primary reject criterion. Other statements don’t reflect universal acceptance rules: welds aren’t required to be perfectly flat or have a finishless surface, since fillet welds commonly have some convexity and finishing requirements vary by project. The idea that the weld size must be kept well above the specified throat isn’t a standard acceptance rule, as welds must meet prescribed throat dimensions rather than exceed them by a large margin. And complete melting of the base metal isn’t a defining criterion for fillet welds; they are designed to achieve fusion at the joint without needing to melt all the base metal.