What defect occurs when a casting solidifies before filling the mold cavity?

When casting solidifies before completely filling the mold cavity, the defect that occurs is called a misrun. A misrun is characterized by an incomplete filling of the mold, which can happen if the metal cools too quickly or if the pouring temperature is too low. This results in a portion of the mold remaining unfilled, leading to weakened parts and a failure to achieve the desired shape of the final product.

In this context, cold shots refer to small globules of metal that solidify in the mold cavity and can lead to integrity issues in the cast product, but they do not specifically result from early solidification preventing mold filling. Cold shuts are related to a lack of fusion between two streams of molten metal within the mold, which is also distinct from the issue of incomplete mold filling. Shrinkage cavities refer to voids left in a casting as the metal cools and solidifies, causing it to contract, but they occur after the mold is filled and typically manifest in a different context. Consequently, misruns are the most appropriate choice for describing the defect caused by early solidification.