Why is the melting point of filler material important in welding?

The melting point of filler material is crucial in welding because it must be lower than that of the base metal. This ensures that the filler material can melt and flow into the joint of the base metals without melting the base materials themselves, which could compromise the integrity of the weld. If the filler material had a melting point higher than that of the base metal, it would not melt properly and would fail to fuse adequately, leading to a weak weld joint.

Choosing a filler material with a melting point lower than that of the base metal allows for controlled heating during the welding process. This is particularly important because it minimizes the risk of warping or deforming the base metal while ensuring a strong bond between the base metals and the filler material. Matching the melting points or having filler material with a melting point higher than the base metal can lead to challenges in achieving a successful weld.

Thus, understanding the relationship between the melting points of filler materials and base metals is essential for producing strong, reliable welds.