5 Cash - Shengsong Zhongbao, Chuan, iron

Issued during the reign of Emperor Ningzong of the Southern Song dynasty, the Shengsong Zhongbao series was struck for only a two-year window as part of a broader effort to manage chronic copper shortages by substituting iron coinage. The Sichuan region — indicated by the "Chuan" mint designation — had long operated semi-independently from central monetary policy, and iron cash struck there circulated largely within the province rather than across the empire.

Sichuan iron coinage of this period is notoriously prone to corrosion, and survivors in collectible condition are genuinely scarce. The province's persistent reliance on iron rather than bronze reflects decades of copper supply disruption caused by Jin dynasty military pressure in the north.