The currency in Wang Mang's era was highly respected for its variety, unique style, exquisite casting and beautiful writing. In addition to fire boxing, there are Daquan 50 and Koizumi Neiyi. Cloth is a thousand miles away, and the rest is thin. It was first cast in the first year of Wangmang Tianfeng (A.D. 14) and continued until the early years of the Eastern Han Dynasty. The material is bronze. I also saw that Qian Wen, who had an iron and copper clip, hung a needle mark, and the pen broke vertically in the spring. The characters of the seller of spring cakes are plain and poorly cast. ). There are nearly 100 versions of biographies, different versions, different styles, reverse folding, forward folding, circular piercing, horizontal strokes, asterisks, moon stripes, final stripes, trimming and so on. Generally, the diameter is 2.2-2.4CM, and the weight is about 2.8-3.6 g, which can reach more than 5 g at the initial stage. It's been handed down from generation to generation. Fire ring is the most common coin in Han Dynasty, and it is the product of the fourth currency reform in the first year of Wangmang Tianfeng (AD 14). Pinquan from the first year of Tianfeng, Emperor Guangwu of the Eastern Han Dynasty, to the 16th year of Jianwu (AD 40) were basically common varieties, among which the versions were double profile, half star, Zuo Ding and You Ding. Most of the marked coins indicate the casting place. Generally, the technology and quality of the double-profile format are better, which may be the early central casting. The inscriptions dotted around should be cast by money stoves in other places. The casting is not very accurate, it may be late. Generally speaking, the size and weight of the early futures spring are not much different, the technology is better and the standardization is higher; However, from the late New Dynasty to the early Eastern Han Dynasty, due to the continuous social unrest and the struggle between various rebel forces and powerful armed forces, the economy was greatly damaged, and a large number of small bad coins and privately minted goods springs appeared. The weight of the spring I have seen in the late private casting is less than half of normal.