What should be the bead width and penetration for a butt weld?

The correct answer indicates that for a butt weld, the recommended bead width and penetration should be between three to five times the thickness of the base metal being welded. This range is essential because it ensures adequate fusion between the two edges of the base metal, which is crucial for developing the desired joint strength.

Proper bead width and penetration allow for a good balance between the strength and ductility of the weld, ensuring that the weld can endure the stresses it may encounter during operation. If the bead width and penetration fall below this recommended range, there is a risk of insufficient weld strength or incomplete fusion, which can lead to weld failure. Conversely, exceeding this range could lead to excessive heat input, causing distortion or damage to the base materials.

Understanding this range helps in achieving a strong and reliable weld, critical for the airworthiness of aircraft structures. It reflects the welding standards that ensure safety and performance in aviation maintenance and repair.