The distinctive feature of the Han Dao (汉刀） is its metal ring at the end of the handle, which acts as a counter balance and also a device for hanging the weapon. The wide use of bronze and iron in China started in the Han period (206 BC to 220 AD); and by early Han, the military had replaced the double-edged sword with Han Dao (汉刀） in the battlefield. The sword often broke upon contact due to the commonly used chopping and hacking techniques during combat. Soldiers soon realised the sword was unsuitable for their type of warfare and the single-edged sabre was the better weapon, which was not only more durable but easier to produce. Shown below are pictures of some typical Han Dao (汉刀）unearthed from various parts of China from the 1950s:
Below is a documentary (with english subtitles) providing more details about the Han Dao/ long sabre:
https://www.youtube.com/watch?v=MtcZmlMJfJY&w=450&h=300&rel=0
Miaodao International - 汉刀,苗刀联合国际网 - the han long sabre & qi jiguang tradition 