What is the purpose of tack welds?

• A. To hold components in alignment and position during fit-up before the full welds are applied.
• B. To finalize the weld and achieve full strength.
• C. To remove burrs after welding.
• D. To improve corrosion resistance.

Answer: (A)

Tack welds are small, temporary welds used to keep parts aligned and positioned during fit-up before the full welds are applied. They act as quick fixtures that hold gaps, angles, and spacing steady so the final welds can be performed accurately without parts shifting when heat is applied. This helps verify fit and reduce distortion once the joint is welded. Tack welds provide minimal strength themselves and are typically removed or blended away after the final weld, rather than contributing to final strength, corrosion resistance, or burr removal.