The common interference of castings in the casting mold during pouring affects the quality, dimensional accuracy, and difficulty coefficient of the precision casting process.

The selection principle of pouring location:

1. The main production and processing surface of precision castings is facing downwards or on the side: during pouring, gas, slag in the molten metal, and sand particles in the mold may float upwards, which may cause defects such as porosity, slag inclusion, and sand holes to occur in the upper part of the casting. However, the possibility of defects occurring in the lower part of the casting results in a denser structure.

The pouring part of the machine tool bed should have the guide rail face downwards to ensure the quality of the main working surface. The quality standard for its circumferential surface is relatively high. By using a vertical pouring scheme, the circumferential surface can be placed on the side and the quality can be balanced and consistent.

2. Large flat downward or inclined pouring of precision castings: Due to the strong thermal radiation of the hot molten metal during pouring on the upper part of the mold, the top sand mold expands, arches, and even cracks, resulting in defects such as sand inclusion and sand holes on the large flat surface. The method of pouring with the large plane facing downwards or using inclined pouring can prevent production casting defects in the large plane.

3. Thin walls of precision castings facing downwards, standing sideways, or tilting: In order to avoid defects such as cold shuts or inability to pour on the thin-walled parts of the casting, the larger thin-walled parts should be placed under the casting or on the sidewalls or tilting parts.

4. The majority of the thickness of precision castings should be placed at the top or on the side of the parting surface, mainly to facilitate the placement of risers for shrinkage at the thick areas.