What is a requirement of the welding procedure for ensuring strong welds?

Maintaining cleanliness of the weld area is essential for ensuring strong welds because contaminants such as oil, grease, rust, and dust can negatively impact the quality of the weld. Clean surfaces allow for better fusion between the base metals and the filler material, which is critical for achieving the desired mechanical properties of the weld. Contaminants can lead to defects such as porosity, lack of fusion, and slag inclusions, which can compromise the integrity and strength of the weld. Therefore, cleanliness is a fundamental requirement in welding procedures to ensure that the welds produced are strong, reliable, and meet the required standards.