Kogai hairpins in a rod like configuration were called 'bo-kogai' (rod hairpins) of which the best quality units were made of the shin bone of a crane and therefore, due to the supposed ability to ward off headache were also preferred by individuals with refined taste.
棒形のものは「棒笄」と呼ばれ、最高級品は鶴の脛の骨で作ったもので、頭痛のまじないにもなると好事家などに好まれたという。