Editing Chinese sword (section)

==Northern and Southern dynasties (420–589)==
[[File:Chinese swords Sui Dynasty about 600 found near Luoyang.jpg|thumb|Sui dynasty swords]]

In the 6th century, Qimu Huaiwen introduced to [[Northern Qi]] the process of 'co-fusion' steelmaking, which used metals of different carbon contents to create steel. Apparently, daos made using this method were capable of penetrating 30 armour lamellae. It's not clear if the armour was of iron or leather.

{{quotation|Huaiwen made sabres [dao 刀] of 'overnight iron' [su tie 宿鐵]. His method was to anneal [shao 燒] powdered cast iron [sheng tie jing 生鐵精] with layers of soft [iron] blanks [ding 鋌, presumably thin plates]. After several days the result is steel [gang 剛]. Soft iron was used for the spine of the sabre; he washed it in the urine of the Five Sacrificial Animals and quench-hardened it in the fat of the Five Sacrificial Animals: [Such a sabre] could penetrate thirty armour lamellae [zha 札]. The 'overnight soft blanks' [Su rou ting 宿柔鋌] cast today [in the Sui period?] by the metallurgists of Xiangguo 襄國 represent a vestige of [Qiwu Huaiwen's] technique. The sabres which they make are still extremely sharp, but they cannot penetrate thirty lamellae.{{sfn|Wagner|2008|p=256}}}}