Hot tears, inclusions, porosity, and cold shuts are:

• A. Forging discontinuities
• B. Casting discontinuities
• C. Welding discontinuities
• D. Processing discontinuities

Answer: (B)

Discontinuities are categorized by where they originate in the manufacturing process, and these four defects come from the casting process as the metal cools and fills the mold. Hot tears are cracks that form when solidifying metal can’t be fed with enough molten metal, often in thick or intricate sections. Inclusions are nonmetallic particles—like mold material or oxide—that get trapped in the metal. Porosity is voids left by gas entrapment or shrinkage during solidification. Cold shuts occur when two streams of molten metal meet but do not fuse completely, leaving a seam. Because these issues arise during pouring and solidification, they are casting discontinuities rather than forging, welding, or processing defects.