Tettei (iron rod) of the Kofun period (tumulus period) may be regarded as equivalent to Kafu (ancient Chinese currency made of bronze,) used as Quasi-money, which is typically represented by Tosen currency (bronze coin shaped like an opened straight razor) of ancient China.
古代中国の刀銭などに代表される準貨幣としての貨布は、古墳時代の鉄?（てってい）などがこれにあたるとの見方がある。