'machine bolt' definitions:

Definition of 'machine bolt'

From: WordNet
noun
A bolt with a square or hexagonal head on one end and a threaded shaft on the other end; tightened with a wrench; used to connect metal parts

Definition of 'machine bolt'

From: GCIDE
  • machine bolt \machine bolt\ n. A threaded hexagonal or square-headed bolt with a nut; it is tightened with a wrench and used to connect metal parts. [WordNet 1.5]