Undercuts are one of the most common welding defects that every welder has to deal with from time to time. Undercutting leaves the welded area weak and prone to cracking. Fortunately, with proper welding techniques, undercuts can be minimized significantly. This is why it is essential to learn what causes undercut in welding so that effective prevention methods can be applied.

Welding is an important trade, and welders produce products that hold a lot of responsibility. If welding is not done right, the result can be catastrophic because parts can break, people can get injured, and reputations can be ruined. One common weakness in welded materials is porosity. This article answers the question: "what is porosity in welding," as well as the causes, how to prevent it, if it can be fixed, and the acceptable amount of porosity in a finished product.