The purpose of a riser is to
A
Deliver molten metal into the mould cavity
B
Act as a reservoir for the molten metal
C
Feed the molten metal to the casting in order to compensate for the shrinkage
D
Deliver the molten metal from pouring basin to gate
Correct Answer: Feed the molten metal to the casting in order to compensate for the shrinkage
A riser, also known as a feeder, is a reservoir built into a metal casting mold to prevent cavities due to shrinkage.Most metals are less dense as a liquid than as a solid so castings shrink upon cooling, which can leave a void at the last point to solidify.