Abstract
Experimental studies were carried out on a riserless casting system utilizing feeding effect through the gating system. In order to get a sound casting, it is necessary that the molten melal is fed through the entire course of shrinkage of the molten metal in the casting, because if a shrinkage cavity is once formed, even though it may later be refilled by the expanding metal in the eutectic solidification process, the refilled area can not be expected to be fully sound. Until the fraction of solid metal in the sprue reaches 0.4 there will be a sufficient feeding effect through the gating system, provided that there is no excessive solidification in the runner and ingate.
