Very high pouring temperature of the metal

Insufficient fluidity of the molten metal

Absorption of gases by the liquid metal

Improper alignment of the mould flasks

Increase in moisture content beyond $$6$$ percent

Increase in permeability

Decrease in permeability

Increase in both moisture content and permeability

Feed the casting at a rate consistent with the rate of solidification

Act as a reservoir for molten metal

Feed molten metal from the pouring basin to the gate

Help feed the casting until all solidification takes place

Uniformly distributed

Forced towards the outer surface

Trapped near the mean radius of the casting

Collected at the center of the casting