In casting and molding, what is the name of the internal solid element placed inside the mold to create a void (hole) in the finished part?

Introduction / Context:
Many cast or molded components require internal passages or holes that cannot be formed by the outer mold cavity alone. A separate insert creates these voids so the final part meets functional requirements (e.g., coolant channels, weight reduction).

Given Data / Assumptions:

• Process: metal casting or plastic molding.
• Need: an internal hole or passage integral to the part.
• Tooling: multi-part mold with removable inserts.

Concept / Approach:
A core is a shaped insert placed inside the cavity to displace material where a hollow feature is required. After solidification or curing, the core is removed (e.g., pulled, broken out, or dissolved), leaving the intended cavity inside the part.

Step-by-Step Solution (conceptual):

Verification / Alternative check:
Inspect the finished part via borescope or sectioning to verify wall thicknesses and hole geometry match the core design.

Why Other Options Are Wrong:

• Cavity: The negative outer shape of the part, not the internal insert.
• Prototype: A trial part, not a tooling component.
• Hole mold: Not a standard term of art.

Common Pitfalls:
Poor core support can cause shift, leading to uneven wall thickness or scrap; designing adequate core prints and vents is essential.

Final Answer:
Core