 The standardization of currency with this round coinage was part of a broader plan to unify weights, measures or axle width during the Qin empire.Ban Liang coins continued to be used under the Western Han dynasty until they were finally replaced by the Wu Zhu cash coins in 118 BC.The Ban Liang coins predate the Chinese Empire and were originally cast during the Warring states period by the State of Qin; these coins circulated alongside cloth money.