For slot welds, what is the minimum spacing lengthwise relative to the slot length?

• A. Spacing shall be equal to the length of the slot
• B. Spacing shall be twice the length of the slot
• C. Spacing shall be four times the length of the slot
• D. Spacing shall be the same as the slot width

Answer: (B)

When evaluating slot welds, the distance between individual welds along the seam must be enough to prevent interference between heat-affected zones and to ensure each weld can develop its full strength. The required minimum is twice the length of the slot. This spacing gives adequate separation so the heat from one weld doesn’t overly affect adjacent areas, helps control distortion and cracking risks, and keeps welds from merging into a single oversized fusion.

Spacing that is only equal to the slot length would be too close, risking overlapping heat-affected zones and weaker performance. Spacing much larger than the minimum is acceptable but not required. Spacing based on the slot width doesn’t relate to the weld’s length and isn’t the specified rule.