Flask (metal casting)

A flask can have any size so long as it is larger than the pattern being used to make the sand mold.

Flasks are often designed with bars that extend to span two opposite sides.

The bars act as reinforcement to the molding sand, which is relatively weak in tensile strength.

The bars help support the sand through the molding and pouring operation.

The number of available flasks of a given size can be a limiting factor in the overall production rate.