Risers are reservoirs of molten metal to supply the solidifying sections of the casting with make-up metal. The molten metal in the risers accomodates liquid-to-solid shrinkage and prevents internal or external voids.

• Risers are placed and sized to provide sufficient metal flow into the mold during cooling to compensate for shrinkage.
• Steel castings have a short metal flow range and a high shrinkage factor.  This requires  large risers that feed uniformly into the casting.

The riser design for the cope pattern should provide the shortest, most direct metal feed into the hottest sections during cooling.  It should be large enough to retain heat and be the last section to cool, so that the final solidification shrinkage is in the riser, not in the casting.

Schematic of Riser Position

Two riser options are shown. Choose the one that bests meets the design criteria