Base metal thickness in a WPS is usually shown as what?

• A. A single fixed thickness
• B. A range
• C. A minimum
• D. A maximum

Answer: (B)

Base metal thickness in a WPS is shown as a range because the same welding procedure is intended to cover a family of thicknesses. The heat input, preheat and interpass temperature, and even deposition parameters can vary with plate thickness, so listing a range keeps the procedure valid for all thicknesses within that interval without needing a separate WPS for each size. A fixed thickness would be too restrictive, while a minimum or maximum alone would exclude either thinner or thicker plates. The range reflects the thickness band for which the procedure has been qualified (and thus is allowed to be used).