Question

Casting yield of a non-pressurized gating system is _____

(a) very high

(b) 80%

(c) very less

(d) 50%

The question was posed to me by my school teacher while I was bunking the class.

The question is from Gating Design topic in section Pattern and Mould, Principles of Gating & Risering of Casting-Forming-Welding I

Answer 1

Right option is (c) very less

To explain: Tapered sprues are invariably used with an unpressurized system. Casting yield of a non-pressurized gating system gets reduced because of the large metal involved in the runner and gates. This makes the wastage of material, to avoid this, a pressurized gating system is used.