Iron cash coins (traditional Chinese: 鐡錢; simplified Chinese: 铁钱; pinyin: tiě qián; Vietnamese: Thiết tiền) are a type of Chinese cash coin that were produced at various times during the monetary history of imperial China as well as in Japan and Vietnam. Iron cash coins were often produced in regions where the supply of copper was insufficient, or as a method of paying for high military expenditures at times of war, as well as for exports at times of trade deficits.