Design Criteria -- The pattern has to be planned and designed so that –

• The parting line is in the largest cross-sectional plane of the casting.
• The component face with the greatest surface detail is in the drag, because fluid fill is better in the drag and low-density, non-metallic inclusions tend to segregate in the cope at the top of the casting .
• The pattern is oriented for continuous, low velocity , non-turbulent fluid flow.
• The need for cores is minimized or  eliminated.

Schematic of Parting Line in a Sand Mold