What is the reduction mentioned for the throat measurement when required by clause 4.3.1.4?

• A. 5 mm (3/16 inch)
• B. No reduction
• C. 3 mm (1/8 inch)
• D. 1 mm (1/32 inch)

Answer: (C)

Throat measurement reduction is used to account for weld geometry in groove welds when evaluating against the standard. In this case, clause 4.3.1.4 requires subtracting a fixed amount from the measured throat before comparing to the required throat size.

You measure the throat as you normally would, then apply a 3 mm (1/8 inch) reduction. Compare this reduced throat value to the specified throat dimension. If it meets or exceeds the required value after the reduction, the throat is acceptable; if not, it’s not.

The 3 mm reduction is the specified value, which is why this option is correct. Reductions of other amounts or no reduction do not align with what the clause requires.