A sprue is the vertical passage through which liquid material is introduced into a mold and it is a large diameter channel through which the material enters the mold. It connects pouring basin to the runner. In many cases it controls the flow of material into the mold.

What is the purpose of sprue well?

ii) Sprue well : It is designed to restrict the free fall of molten metal by directing it in a right angle towards the runner. It aids in reducing turbulence and air aspiration.

What is the importance of sprue base design?

The purpose of the sprue system is to hold the wax patterns in place until the wax tree is invested and then provide a route for that wax to drain out of the invested mold.