五寸釘[gosunkugi] long nail
間釘[aikugi] double-pointed nail
出る釘は打たれる[derukugihautareru] the nail which sticks out gets hammered down (used to encourage conformity)
切り釘[kirikugi] brad
裏釘[urakugi] nail sticking through

装釘[soutei] binding (book)
釘抜き[kuginuki] pincers
金釘流[kanakugiryuu] a scrawl
ねじ釘[nejikugi] screw

データの先頭[deetanosentou] beginning of data
一頭[ittou] one large animal (horses, cattle, etc.)
一頭立て[ittoudate] one-horse (carriage)
咽頭[intou] pharynx
駅頭[ekitou] station

音頭[ondo] leading a group of people
会頭[kaitou] society president
街頭[gaitou] in the street
核弾頭[kakudantou] nuclear warhead
巻頭[kantou] opening page of book