In welding, what does "penetration" refer to?

Penetration in welding specifically refers to the depth of the weld pool into the base materials being joined. A deeper penetration means that the molten weld metal has effectively fused into the base materials, creating a strong bond that contributes to the overall integrity and strength of the weld joint. Achieving the correct penetration is crucial, as insufficient penetration can lead to weak joints that lack the necessary strength, while excessive penetration may result in distortion or burn-through of the base materials.

Understanding penetration is key for welders to control the weld quality and ensure that the bond formed meets the required specifications for the application, whether it be structural, aesthetic, or functional.