There is a particularly common misconception that Japanese swordsmiths do not use power tools, and that everything is hand-made. Here is a video of master Hirokuni Hiroki (a mukansa level smith, that is a master of masters, mukansa means without or beyond judgement) using a power hammer. Japanese smiths are very strict about the quality of their work, but they are human just like us, and using a powerhammer doesn't mean that the work still does not require considerable skill.
As our iaido teacher eloquently put it, the famous smiths that have many apprentices can have them do the heavy work, whereas lesser known smiths, for lack of manpower, will use a power hammer.
As our iaido teacher eloquently put it, the famous smiths that have many apprentices can have them do the heavy work, whereas lesser known smiths, for lack of manpower, will use a power hammer.