The negative space within a tool, mold, or mechanical part that dictates the shape of a cast or molded product. In solid modeling and machining, it refers to any internal pocket or void created by removing material. The precise geometry, surface finish, and draft angles of a cavity are critical for allowing the final part to release cleanly without damage.
Heard on the job
The injection pressure is too low to fill the mold cavity completely, leaving voids in the plastic part.