Select a characteristic of a good gas weld

• A. The depth of the penetration shall be sufficient to ensure fusion of the filler rod
• B. The height of the weld bead should be 1/8 inch above the base metal
• C. The weld should taper off smoothly into the base metal
• D. The weld should be perfectly flat with sharp edges

Answer: (C)

In gas welding, the strongest joints come from a smooth, gradual transition where the weld metal blends into the base metal. A good weld should taper off smoothly into the base metal, indicating controlled heat input and proper fusion between the filler and the parent material. This gentle taper creates a continuous bond, reduces stress concentrations, and yields a sound contour without abrupt edges or excessive buildup.

Bead height that sits too high suggests over-reinforcement, which can cause distortion and weak points; a perfectly flat bead with sharp edges indicates poor contour and insufficient fusion. Focusing only on fusing the filler rod would neglect the essential fusion with the base metal, which is necessary for a durable weld.