Mould cavity-

The mould cavity which holds the liquid metal is complementary to the final product. The mould material, therefore, must withstand the superheated liquid metal. For single castings, the mould is cereal, with water.

Shake allowance-

The vertical faces of mould cavity gets enlarged due to shaking or tapping of pattern for easy removal from mould. This causes slight enlargement of mould cavities and often a negative allowance in the form of shake allowance is provided to compensate for this enlargement.