is nail
is terrible picture of nail
is nail with funny head
is not nail; is pointy wire
is NAIL
is especially irritating form of not-nail
is somewhere between nail and not-nail
is screw
is screw made of hateful metal
is small screws made of hateful metal; note solid neck, tapered threads
is not screw; is cunning devil come from hell to plague living by shearing off in hole when too late to remove