Veli Posted February 1, 2009 Report Posted February 1, 2009 I bought a Yamato Tegai waki from AOI Art some time ago. I could afford it because it was "slender" i.e. seen a lot of polishing. Still, it had hakikake boshi, nice jigane, raised shinogi, bright suguha hamon and it is probably very old. It also has Tokubetsu Kicho papers. But still - no more polishing for this blade. I had this blade with me in a local gun show, where I discussed it with a friend that knows something about Nihon-to. He stated that the blade has lost "a lot of millimeters" from its original width. I replied - optimistically - "well, 2-3 mm, I think". Then it occurred to me that I simply do not know. I was mentally comparing the ha width with the photos of high-quality Yamato blades. But how much width have they lost? I'd be happy if any of the more experienced members would like to give a guess about how much the wakizashi in question has lost from its original width. I have attached a few photos of the blade. The present measurements are: Motohaba 24.6 mm; Sakihaba 17.7 mm; Motokasane 0.6 mm; Nagasa 51.2 cm; Quote
John A Stuart Posted February 1, 2009 Report Posted February 1, 2009 I have a Yamato blade, not Tegai, ko-Mihara, that has an hoso-suguba hamon with these dimensions. Sori-toriizori, 2cm Mune-iorimune Nagasa-68.5cm Shinogizukuri Motokasane- 0.7cm Motohaba-3.0cm Sakihaba-0.7cm Shinogi-high Jihada-itame Hamon- hososuguba w/ nie Horimono-bohi, kakinagashi, hisakiagari Boshi-omaru Kissaki-chukissaki. It is still a robust blade with minor ware in the hi. John Quote
loiner1965 Posted February 1, 2009 Report Posted February 1, 2009 i had a yamato o-wakizashi and it was a real beefy blade probarbly made late 1700 early 1800 and the polisher said it was the hardest sharpest thing he had ever come across....told me he wore kevlar gloves when he polished it....wether he was kidding me or not that blade was real scary to handle Quote
uwe Posted February 1, 2009 Report Posted February 1, 2009 Hi Veli, if your sword really have motokasane of 0,6mm, then its obviously polished a good many times :lol: Seriously, it`s not so easy to find out how much wide (mihaba) a blade have lost over times. Usually you had to look at the mune and compare the thickness of nakago with the thickness of the blade, then you can make an appraisal of the situation. Unfortunately,this says nothing about changes of mihaba Uwe Quote
leo Posted February 1, 2009 Report Posted February 1, 2009 Hi Vell! The blade just has complete yakiba, but as you have already realized, another polish would convert your blade into a "study piece". Your friend is right, this blade has lost more than 2 or 3 mm. The healthiest old Tegai blades (usually end of Kamakura or Nanbokuchyo) I have seen had about 5 to 6mm yakiba. If you add 2mm for previous reduction, you end up with about 8mm original yakiba. This is a rough estimate, but probably comes close. This means suguha, with notare or midare draw your own conclusions. I include a picture of a nice end-of-Kamakura Yamato Tegai tachi. Regards, Martin Quote
Veli Posted February 1, 2009 Author Report Posted February 1, 2009 Hi! Thanks for info! Sorry! Uwe, thanks for the correction! the situation is luckily not that bad :D . The correct measurement is 0.6 cm. Yes, there is a difference in nakago and blade thicknesses, but nothing too drastic. Maybe I could calculate an estimate of the mihaba reduction by assuming that the togishi have preserved the original cross-section geometry and using the abovementioned difference as a scaling factor... John, what is the approx ha width of your ko-mihara blade? Can you estimate the average distance from the hamon to the cutting edge? You probably meant sakikasane-0.7 cm??? Or else I win (after correcting my unit mistake) the second place only in competition for the most slender blade . If you have a measurement for the sakihaba, it would help me a lot! Steve, do not worry! I still have the two fingers needed for typing replies Martin, what a beautiful jihada you have there! Yes, near the hamachi my waki's ha is very narrow, but as you can see in the photos, it has a couple of millimeters more ha width closer to kissaki. In any case, we could estimate it has lost something like 5 mm. Thanks to all of you for good answers! Quote
loiner1965 Posted February 1, 2009 Report Posted February 1, 2009 Hi! Thanks for info! Sorry! Uwe, thanks for the correction! the situation is luckily not that bad :D . The correct measurement is 0.6 cm. Yes, there is a difference in nakago and blade thicknesses, but nothing too drastic. Maybe I could calculate an estimate of the mihaba reduction by assuming that the togishi have preserved the original cross-section geometry and using the abovementioned difference as a scaling factor... John, what is the approx ha width of your ko-mihara blade? Can you estimate the average distance from the hamon to the cutting edge? You probably meant sakikasane-0.7 cm??? Or else I win (after correcting my unit mistake) the second place only in competition for the most slender blade . If you have a measurement for the sakihaba, it would help me a lot! Steve, do not worry! I still have the two fingers needed for typing replies Martin, what a beautiful jihada you have there! Yes, near the hamachi my waki's ha is very narrow, but as you can see in the photos, it has a couple of millimeters more ha width closer to kissaki. In any case, we could estimate it has lost something like 5 mm. Thanks to all of you for good answers! beautiful blade never the less but has you say the hamon runs very close to the ha now so keep it well oiled :D Quote
John A Stuart Posted February 1, 2009 Report Posted February 1, 2009 Sorry Veli, Sakikasane-0.7cm Sakihaba-2.3cm The width you requested is averaged at 0.3cm even the boshi is the same. John see here http://www.johnstuart.biz/new_page_4.htm Quote
nihonto1001 Posted February 2, 2009 Report Posted February 2, 2009 There is at least one juyo token Tegai Kanenaga with maximum 6mm thickness at the shinogi near the habaki. It does not look like it was ever much wider judging by the maximum thickness of the nakago (about 1.5mm more). Some smiths worked with thin kasane, such as Miike Mitsuyo, perhaps to make the blade lighter. Maybe some Tegai smiths worked in this way too. An interesting question indeed. Jon Quote
Veli Posted February 2, 2009 Author Report Posted February 2, 2009 I measured the maximum thickness of the nakago: it was 7.5 mm. The maximum thickness (shinogi to shinogi) of the blade approximately 1 cm above hamachi is 6.5 mm. We could assume that the blade dimensions have been reduced by a factor of 7.5/6.5 = 1.154. If we multiply the motohaba (24.6 mm) and sakihaba (17.7 mm) by 1.154 ,we should have an estimate of the original width: motohaba 28.38 mm, sakihaba 20.42. Thus the original yakiba width has been 1 mm (average present width) + (28.38 - 24.60) = 4.78 mm at the hamachi, and 2.3 mm (present width) + (20.42-17.7 mm) = 5.04 mm at the yokote. The original yakiba width would have been about 5 mm, and it has been reduced by 2.5 - 4 mm. Doesn't sound too much. Could this be correct? Quote
John A Stuart Posted February 2, 2009 Report Posted February 2, 2009 Sounds too much to me. You have to adjust for the original niku. More kasane could be removed than haba by reducing niku. No? John Quote
uwe Posted February 2, 2009 Report Posted February 2, 2009 definitely too much, in my opinion ......compared with the wide of the hamon. You have to consider, that not a few yamato blades showing originally hoso-suguha ( like my sue tegai nagamaki naoshi, or my recently bought kongoboje katana) Anyhow, an interesting topic Uwe Quote
Veli Posted February 3, 2009 Author Report Posted February 3, 2009 Could we then conclude that the yakiba of my Tegai waki has been reduced by 1-6 mm :D Seriously, maybe the 2-3 mm estimate was not too far Thanks to all of you for your valuable opinions! Quote
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