What is a common effect of insufficient penetration during welding?

Insufficient penetration during welding directly results in decreased weld strength. This condition occurs when the weld metal fails to adequately fuse with the base metal, leaving a weak joint that is more susceptible to failure under stress. A properly made weld requires adequate penetration to ensure the materials are bonded effectively throughout their thickness. When penetration is insufficient, it creates regions within the weld that cannot adequately support loads, which can lead to cracks or complete joint failure during use.

Other options, such as increased heat resistance, better visual appeal, and enhanced corrosion resistance, do not accurately reflect the consequences of insufficient penetration. In fact, if penetration is lacking, it is likely to lead to a weaker weld that is less capable of withstanding environmental factors, which can actually increase susceptibility to corrosion and fatigue.