The assembly of channels which facilitates the molten metal to enter into the mold cavity is called the gating system (Figure17).Alternatively, the gating system refers to all passage ways through which molten metal passes to enter into the mold cavity.The nomenclature of gating system depends upon the function of different channels which they perform.
Down gates or spruce
Cross gates or runners
Inmates or gates
The metal flows down from the pouring basin or pouring cup into the down gate or spruce and passes through the cross gate or channels and inmates or gates before entering into the mold cavity.