Ethnographic Arms & Armour - View Single Post

t_c · 1st July 2006, 04:40 AM

Hi, I hate to be the one to say this, but I think you may have something other than a 17th or 18th century piece. I am not an expert on Japanese swords, but I have had the opportunity to inspect a number. If I am wrong about this I hope that someone will please correct me.

My observations:

For the japanese sword some dating is done by the condition of the tang. The rust tends to be uniform from the uniformity of moisture in the wooden core. This piece shows what appears to be slag, not rust, with bright steel underneath. (Slag is the surface oxidation that develops after a "heat" by placing the blade in a furnace and then exposing it to the air). Surface rust that is apparent in older pieces has a tendancy (from what I have seen) to gently deteriorate sharp edges into softer more rounded edges, whereas the signature on this tang has some quite sharp lines in certain areas.

Another way to judge the date of a japanese sword is to try to determine how many times it has been polished. When a japanese sword is polished it is polished from the area covered by the Habaki (not present here) lengthwise all the way down the blade. What happens over repeated polishings is that the tang (which represents the original forged thickness of the blade) ends up being quite thicker than the rest of the blade (the thickness develops a pronounced taper in towards the blade). Look for this in the thickness of the tang as it becomes the blade right at the muni-machi (back notch - where the spine "steps" into tang).

To further validate the age of your piece take a moment to look at the tsuba. When a tsuba is fitted to a blade, it is "punched" in four corners (either side of the front edge, and either side of the back edge). This is much the same concept as center-punching to prep for a drilling. The metal is pushed into the void where the blade passes through and then filed down to fit the cross section of the blade so that the fit is snug and well aligned. These punch marks should be somewhat distinct. Sometimes tsuba are cast and these marks are much softer in their form (if they have not been re-punched to fit the blade). This may also help you shed some light on your piece.

The unfortunate truth about signatures on Japanese swords is that they tend to be well documented and therefore easily researched. I find that one must rely on more than just a signature to date a sword properly.

I hope this all helps, and if someone has different ideas about this piece, or if my understanding of the processes described are erronous (it has been a while since I was around the japanese stuff ) please chime in.

1st July 2006, 04:40 AM	#3
t_c Member Join Date: Jun 2006 Location: ca, usa Posts: 92	Hi, I hate to be the one to say this, but I think you may have something other than a 17th or 18th century piece. I am not an expert on Japanese swords, but I have had the opportunity to inspect a number. If I am wrong about this I hope that someone will please correct me. My observations: For the japanese sword some dating is done by the condition of the tang. The rust tends to be uniform from the uniformity of moisture in the wooden core. This piece shows what appears to be slag, not rust, with bright steel underneath. (Slag is the surface oxidation that develops after a "heat" by placing the blade in a furnace and then exposing it to the air). Surface rust that is apparent in older pieces has a tendancy (from what I have seen) to gently deteriorate sharp edges into softer more rounded edges, whereas the signature on this tang has some quite sharp lines in certain areas. Another way to judge the date of a japanese sword is to try to determine how many times it has been polished. When a japanese sword is polished it is polished from the area covered by the Habaki (not present here) lengthwise all the way down the blade. What happens over repeated polishings is that the tang (which represents the original forged thickness of the blade) ends up being quite thicker than the rest of the blade (the thickness develops a pronounced taper in towards the blade). Look for this in the thickness of the tang as it becomes the blade right at the muni-machi (back notch - where the spine "steps" into tang). To further validate the age of your piece take a moment to look at the tsuba. When a tsuba is fitted to a blade, it is "punched" in four corners (either side of the front edge, and either side of the back edge). This is much the same concept as center-punching to prep for a drilling. The metal is pushed into the void where the blade passes through and then filed down to fit the cross section of the blade so that the fit is snug and well aligned. These punch marks should be somewhat distinct. Sometimes tsuba are cast and these marks are much softer in their form (if they have not been re-punched to fit the blade). This may also help you shed some light on your piece. The unfortunate truth about signatures on Japanese swords is that they tend to be well documented and therefore easily researched. I find that one must rely on more than just a signature to date a sword properly. I hope this all helps, and if someone has different ideas about this piece, or if my understanding of the processes described are erronous (it has been a while since I was around the japanese stuff ) please chime in.