Which statement differentiates soldering from laser welding in metal framework fabrication?

• A. Soldering uses a filler metal to join parts; laser welding fuses parts directly.
• B. Soldering fuses parts directly and laser welding uses filler metal.
• C. Both methods require filler metal.
• D. Laser welding results in more distortion than soldering.

Answer: (A)

The main distinction is how the joint is formed. Soldering relies on a filler metal that melts at a lower temperature than the parts being joined; the base pieces stay solid, and the liquid filler wicks into the joint and bonds as it cools. Laser welding, on the other hand, uses a focused laser to melt the base metals themselves, fusing the parts directly with no separate filler metal in the typical process. This difference explains why soldered joints are created with filler metal and laser-welded joints are true fusion joints. The other statements either swap the roles of filler metal and fusion or claim filler is required in both, which doesn’t match how these methods actually work.