While technically, all screenused props are "made for the production" as well, the way the term in used by hobbyists refers to the unused items. If the piece is screenused, it will be called screenused.
They usually come in three forms:
1. Exact copies of screenused pieces that were just extras in case the originals were damaged and were not needed (and thus were not used on film).
2. Pieces whose design was made for use but either cut out of a scene from the film, or just never used.
3. Preliminary test pieces, initial designs that were later altered or abandoned, and prototypes.