bolts

Metal plugs ending in a head and threaded so they can be tightly screwed into nuts to secure fastenings and assemblies.

bolt

Metal threaded plug ending in a head; it is tightly screwed into a nut to secure fastenings and assemblies.

nut

Hollow cylinder of metal whose lining is threaded to screw onto a corresponding bolt.

head

Widened end of the bolt, of various shapes and sizes.

shoulder bolt

Bolt whose head comprises a section of smaller diameter for concentrating the tightening pressure.

threaded rod

Elongated part whose surface has a spiral protrusion for screwing into a corresponding nut.

shoulder

Cylindrical nonthreaded protrusion used as a bracket as the bolt is being tightened.