When interpreting a welding blueprint, a specific weld is indicated as a 'Square-Groove Weld' with a root opening of 3 mm (1/8 in.) and no other size specified. The symbol is shown only on the arrow side. What does the absence of a depth of preparation or weld size number imply for a square-groove weld?

Question: When interpreting a welding blueprint, a specific weld is indicated as a 'Square-Groove Weld' with a root opening of 3 mm (1/8 in.) and no other size specified. The symbol is shown only on the arrow side. What does the absence of a depth of preparation or weld size number imply for a square-groove weld?

Answer options:

• The weld is a partial penetration square-groove weld. ✅ The weld is a complete joint penetration square-groove weld.
• The weld should be filled to a specific height, which is indicated by a separate general note.
• The weld preparation should be assumed to be 6 mm (1/4 in.) deep.

Correct answer: The weld is a complete joint penetration square-groove weld.

Explanation: For square-groove welds, if no depth of preparation or weld size is specified to the left of the weld symbol, it implies that the weld is a complete joint penetration (CJP) weld. The root opening of 3 mm is still specified, but the weld depth is meant to extend through the full thickness of the joint. Distractors like partial penetration or assumed depths are incorrect without explicit notation.