In 1739, the minting of one-mon iron coin started at zeniza located in Jumantsubo of Fukagawa in Edo, Ishinomaki of Sendai, Oshiage of Honjo (Sumida Ward) in Edo, and so on, due to correction of high market price of currency and short supply of materials.
元文4年（1738年）には銭相場の高値是正および材料の銅の供給不足などから、江戸深川十万坪、仙台石巻、江戸本所(墨田区)押上などの銭座で鉄一文銭の鋳造が始まった。