Emil

I agree with you, it's probably a better idea to display an iaito. Just out of curiosity, some Japanese sword shops that I've been to, display their blades in open air all day long, every day. This one for example displays probably a hundred blades outside of both koshirae and shirasya, some of them with a pricetag up to 2.3M JPY. They have a rack of 10-20 Shinsakuto sold only in Koshirae, you don't even get a Shirasaya. And they are also displayed in open air. I was curious to how they manage to maintain all those swords while customers are free to walk around and breathe on them.

I recently gifted my father a Showato in traditional Shirasaya and Koshirae that I bought from Aoi Art along with a kiri bako for ideal storage. He wants to enjoy this sword by storing it in Koshirae on a wall hanger at up to a week at a time. As I've mentioned in another post it already has some tiny rust spots along the blade and I don't want to make it worse, but I do understand his desire to showcase it for a few days occasionally. Any advice on storing a katana sitting in its Koshirae on a wall openly? Should I tell him it's better to just display the Koshirae with the tsunagi? Or is one week at a time in Koshirae fine? I already told him not to put the wall hanger close to the fireplace or windows to save the lacquer from rapid changes in temperature and direct sunlight. Any advice would be highly appreciated

Hi Paul! Yes that's the book I was looking for, and any references to Swedish steel in it. I believe Bruce got me everything in there already. Thank you!

I'll try that, thanks 👍

I think I'm over oiling the blade, but since there are a few rust spots already I'm afraid to leave it too dry

Here are some close ups of the hada and hamon that I managed to take with a 30x and 60x magnifier along with some photos of the blade in direct sunlight @John C @Gilles

It looks like this every now and then when I open it

I managed to take some close ups with 30x and 60x magnification

Thanks for the advice @French nihonto and @Matsunoki How concerned should I be about the Shirasaya leaving wooden residue on the blade?

It has actually crossed my mind, if it would be possible to shave of a tiny part of the tang for the purpose of historical analysis, I wouldn't be opossed to it. The problem is I have no idea who or where to turn to for metal analysis. It's not a common service.

That sounds fantastic Jean, I hope you can do it! I'm really looking forward to see if you can get any results. If your railway steel is pre 1860, it's a very high chance that it's puddled steel. The bessemer technique was invented 1856 and gained popularity during the 1860s. As I understand it, the first railroads were laid with puddled steel in Japan. However, very early on they switched to the more advantageous bessemer steel. For the best Showa-to swords, only puddled steel would have been used as bessemer steel were too homogeneous to produce any hada. It's claimed that the best showato made from railway steel were commonly water quenched, which produced the finest tier of Showato, not easily distinguished from Gendaito, hence the nickname "Mill-steel gendaito" this even resulted in a problem of having wartime smiths selling these showato as traditional gendaito at higher prices, some smiths were actually jailed for it. And as I understand it, this later led to the introduction of showato stamps. I'm not entirely sure if my blade falls into that category of top tier showato or not. Since the blade lenght of my sword is 69 cm / 27.2 inches it's already a strong indicator that this was a special ordered Showa-to. And even for collectors it might not be the easiest sword to distinguish from a traditionally made one. However, the concensus in this thread seems to be that my sword is probably oil quenched. But I'm guessing that since the wartime production wasn't always an exact science it's very possible that a special ordered showato could be produced with the "finer" puddled railway steel and still be oil quenched. Prehaps the source claiming that railway steel blades were water quenched is not entirely accurate or it just wasn't always the case.

Thanks @Brian, I tried it but without any luck. I think the problem is that the toothpick is larger than rust pits and they felt very sturdy.

Here's where my prehaps biased speculation comes into the picture. Because the blade obviously has some kind of hada, however not necessarily what you'd expect from tamahagane it points to some of the steels that were known to produce a similar pattern, like puddled Swedish railway steel

Upon closer examination of a katana I recently gifted my father, I see small dots along the blade. 2 months ago, when it first arrived with at my brother’s, he sent me pictures of it. I saw the small grey dots but assumed it was just dust. So it doesn't appear to have worsened in the last two months. Mostly they the spots go unnoticed, but I can see that they have a yellowish tone if I look really close in some light conditions. I advised my dad to keep it well oiled at all times. However, every time it's pulled from the shirasaya there are small wooden flakes on the blade. It's probably been stored in this shirasaya for many years already, judging from the aged look of it. What is my best course of action to prevent further oxidation? What would you have done in regards to blade and shirasya? Now that this licensed Showato has left Japan and the torokusho has been returned, there are no guarantees that it will pass inspections and be let inside Japan ever again. Let alone the price of a polish, I'm quite concerned that if left as is, it might get worse?

Now that I do have the sword in hand, I tried to look at these. I believe I can see the martensite crystals but in some lighting conditions (see my photos) it also looks like a shadow. I'm not confident enough to draw any conclusions