Which weld defect may be caused by heat settings that are too high, travel speed too slow, stick out that is too short, incorrect welding gun angles, and root caps that are too wide?

• A. Burn through
• B. Porosity
• C. Penetration
• D. Distortion

Answer: (A)

Excess heat input into the weld area is the key factor. When heat settings are too high and travel speed is too slow, the weld pool stays hot and the surrounding metal doesn’t have time to dissipate the heat, so the base metal at the root can melt through. A stick-out that’s too short concentrates the arc and adds even more heat into a small area, while incorrect gun angles can direct heat in a way that hotspots the joint, and a root cap that’s too wide means more heat and metal at the root to contend with. Together, these conditions push you toward burn-through, where the metal at the root is penetrated entirely rather than just properly fused. Porosity or distortion arise from other issues (shielding gas/contamination for porosity; general heat management for distortion), but the described combination most directly leads to burn-through.