What is the purpose of back stepping or weaving in multipass welds?

• A. To reduce the time of welding only.
• B. To eliminate the need for post-weld inspection.
• C. To distribute heat, control distortion, and improve weld penetration and uniformity.
• D. To use less filler metal.

Answer: (C)

Back stepping and weaving are heat-control techniques used in multipass welds to manage how energy is applied along the joint. By stepping the arc backward a bit with each pass or moving the arc side to side, heat is spread more evenly instead of concentrating in one spot. That even heat distribution helps minimize distortion and residual stress, and it also promotes deeper, more uniform penetration and consistent filler deposition across each pass. The result is a weld with better fusion at both the root and the cap and a smoother, more uniform bead. They’re about controlling heat and quality, not about speeding up the work, skipping inspections, or using less filler metal.