During plug weld preparation, holes are drilled or punched in the same locations as the spot welds being replaced. What is the purpose of these holes?

• A. To relieve internal stresses
• B. To provide venting
• C. To align parts
• D. To create holes for plug welding

Answer: (D)

When you prep for plug welding, the holes are placed exactly where the original spot welds were. These openings give you a controlled path for the weld heat to reach the bottom sheet, so you can fuse the top and bottom panels together through the hole. In effect, each hole becomes a plug weld, restoring the joint’s strength with a defined weld nugget and avoiding excessive burn-through on the outer surface. The holes aren’t primarily about relieving stresses or venting; they’re there to create reliable access points for the plug welds and to ensure the panels join cleanly and with proper alignment.