Casting defect if the metal penetration of the sand mold is in the size range of the sand grains at maximum (see Sand grain).
For sand casting and shell casting, the roughness depth (Fig. 1)generally depends on the grain of the used mold material. Instead of direct measurements of the castingsurface roughness, standardized surfaces according to DIN EN 1370 are often applied for examination of the surface roughness (see Surface quality) by means of comparators (Fig. 2).
Mold sand-based casting defect