What is the purpose of the filler metal in welding?

The role of filler metal in welding primarily focuses on adding material to the weld joint, which enhances the strength and integrity of the joint once it cools and solidifies. When filler metal is melted in the welding process, it combines with the base metals being joined, allowing for a seamless transition and a bond that is often as strong, if not stronger, than the base materials themselves.

The correct purpose of filler metal is not directly tied to controlling the heat of the weld pool or maintaining it at its melting point. Instead, it serves to fill the gap between the two metals being joined, ensuring that there are no weak sections in the weld.

While certain aspects of heat control and surface cleaning may involve other techniques or additional materials, the primary function of the filler metal is to contribute additional strength to the weld, forming a robust joint that can withstand mechanical stresses. This understanding of filler metal's contribution is foundational in welding practices, enabling successful joins across various applications in engineering.