Katana with practice blades.......

[7Cain]

A friend of mine has a katana that is very old looking, however the blade does not look original. The katana has formal dress in traditional black drab and very authentic looking, however the blade it's self has a flat edge, and no hamon. I have not removed the blade to look at its tang for signature, but my guess was that some time ago, the original blade was replaced by a nonfunctional blade, or it was a very well made replica. My friend thinks that the blade is the original that was ground down for practice, but I don't think that anyone who owns a katana would do that to an authentic blade plus there is no evidence of any lamination or tempering. My question is, was it common for families to remove the live steel and replace it with a blank when the sword was not in use? Or is more likely that this particular piece is convincing copy?

 

[WrongFriend]

As far as I've heard and read there were rarely copy fake blades for practice. Most practice was done by bokken. Bamboo swords are relatively new invention that doesn't harm but its sound makes judgement easier. In those days, some serious practice was made with "habiki = sword with its edge dulled out." Copy blades have been used after WWII, most of which are made of non-ferrous metal not to modified into real functional swords.

Hamon on katana is subtle, grinding by grinder or polishing by buff wheel can erase hamon on base metal. If there were given too much heat, the heat treat could have been ruined.
The katana may more possibly be a showato made of spring steel. It was last katana made for practical purpose, militaly use. Today in Japan, not many of them remains and new one is never made again by lagality reason.

All these are just my guesses. If you can attach a pic, I think Robert can give you answer.