08 Discontinuities and defects · 10 min
Defect versus discontinuity
A discontinuity is an interruption. A defect is a discontinuity that fails the standard. Cracks are almost never a debate.
Porosity that sits under the diameter and spacing limit is a discontinuity and still acceptable. The same pore over the limit is a defect. Your opinion of ‘ugly’ is not a criterion. The product standard is.
Cracks of any size in weld metal or HAZ are typically rejectable in structural work. Incomplete fusion is typically rejectable. Incomplete penetration is rejectable when CJP was required. Everything else is a measured comparison: undercut depth and length, reinforcement height, porosity sum of diameters, fillet size, overlap (usually a defect because it is unfused metal at the toe).
Open the Fault bay next. Drill every sample until the name, the cause, and the typical accept/reject logic are automatic. Then practise the report sentence.