In a metal casting process to manufacture parts, both patterns and moulds provide shape by dictating where the material should or should not go. Which of the option(s) given correctly describe(s) the mould and the pattern?

The correct option is: Patterns can be used to make moulds.

To understand why this option is correct, let us break down the definitions and roles of patterns and moulds in the metal casting process:

1. What is a Pattern?
A pattern is a physical replica or model of the final part to be cast, though it is typically made slightly larger to account for metal shrinkage and machining allowances. The pattern is used to pack or shape the moulding material (such as sand) around it to form the cavity.

2. What is a Mould?
A mould is the hollow cavity (container) into which molten metal is poured. The shape of this cavity corresponds exactly to the external shape of the part to be produced. The molten metal cools and solidifies within this cavity to take the shape of the desired part.

3. Relationship between Patterns and Moulds:
In casting, the mould cavity is created by placing the pattern in a flask (moulding box) and packing sand or other mould materials around it. Once the moulding material is packed firmly, the pattern is carefully removed, leaving behind a hollow impression (cavity) of the desired shape. Therefore, patterns are used to make moulds. Conversely, moulds are not used to make patterns in typical sand casting, making the option "Patterns can be used to make moulds" correct.