In QA, what is the difference between a defect and a fit-up issue?

• A. A defect is misalignment and a fit-up issue is a flaw in the weld.
• B. A defect is the flaw in the weld itself; fit-up issue is a misalignment or gap before welding that can cause rejection or rework.
• C. A defect is any issue during welding; a fit-up issue is the quality of filler metal.
• D. A defect is the presence of porosity only; a fit-up issue is the lack of penetration.

Answer: (B)

In QA, the difference is that a defect is a flaw in the weld itself after it has been made, whereas a fit-up issue is about the joints before welding—how the pieces are aligned and whether there is a gap that will affect the weld. A common defect involves features that show the weld did not meet quality standards, such as porosity, cracks, or lack of fusion. A fit-up issue is misalignment, an improper gap, or incorrect bevels on the joint that can lead to rejection or rework if not corrected before welding. This distinction matters because you fix fit-up during preparation to prevent defects, and you address defects after welding with repairs or rejection. The other statements mix these concepts: porosity and lack of penetration describe weld flaws, not fit-up; and describing fit-up by the quality of filler metal doesn’t fit, since filler metal quality is a separate material/process issue, not about how the joints are prepared.