hook and eyes 
Fasteners formed of a metal hook inserted into a round eye or a straight eye.
hook 
Curved piece that fits into a round eye or a straight eye to attach or do up a garment.
snap 
Fastening mechanism made of a socket disk and a ball disk that snap shut when pressed together.
safety pin 
Curved metal stem that forms a spring; the pointed extremity of its flexible arm is kept in place by a hook.