What is the main purpose of using filler materials in welding?

The primary purpose of using filler materials in welding is to provide additional strength and support to the welded joint. Filler materials are added to help bridge the gap between the base materials being joined, ensuring that the weld can effectively resist stresses and loads once the joint has cooled and solidified. This is essential in maintaining the structural integrity of the welded assembly.

Filler materials can also help improve the metallurgical properties of the weld, such as toughness and ductility, which are important for the weld's performance under various conditions. They help to create a cohesive bond between the materials, ensuring a strong and durable connection that can withstand application demands. While aesthetic considerations, speed of welding, and insulation might hold some relevance in specific contexts, the main goal of filler material is to enhance the strength of the welded joint.