Nihonto Care.... the RIGHT way in the modern world


Amateur Togishi
Staff member
Aug 25, 2018
Alright. I'm going to post this in the hopes that folks leave the antiquated ways of nihonto care behind. This post may be controversial to some, but should come as no shock to those familiar with the nihonto world and its emerging practices.

Caveat emptor: this post is NOT intended to be relevant for modern mono steel or even pattern welded katana. This post is intended for nihonto, gendaito and/or shinsakuto that are meant to be preserved for centuries with an attempt to minimize the need for polishes. These methods will work for any blade but are overkill for the reproduction katana. I will do a separate and shorter thread covering my care methods for those.

Let's begin with the controversial statement. Now, listen carefully: take your uchiko... find the nearest trash can... and THROW IT AWAY!!!!!

yep. I said it. It's awful for your sword. And very error prone. In fact, the likelihood you will damage your valuable nihonto far exceeds the likelihood you will attain intended cleaning results.

Why is that, you ask? Uchiko is a POLISH. You are not cleaning, you are polishing the blade. Uchiko powder is the remnant powder collected from the togishi process by collecting and sorting the fine powder left over from the uchigamori stone phase of the polishing of a nihonto. And often times retail uchiko is actually not real uchiko at all but the harder and more coarse grained talc. You find this stuff in "cleaning kits" all over the place.

By banging an abrasive on your blade you run the risk of abrasions and you can very well do much worse damage on the blade than simply removing residual oil which was the intent.

So, what do you use instead? Microfiber. Specifically, one of the best clothes for oil removal from a nihonto is the "microdear" microfiber. This stuff is great and will never scratch or abrade your precious blade.

Once you remove the main coating of oil, I use another pass (with another fragment of microdear cloth) where the cloth is covered with 99% pure isopropyl alcohol. This ensures that any residual oil is removed and isopropyl's 1% moisture evaporates so quickly that it won't endanger moisture getting on the blade.

Finally I use a 3rd pass (with yet another clean strip) of microdear. This ensures any residual alcohol is removed and you have a completely bare blade.

Now to apply a new coating of oil I personally use the stiffer microfiber made by Toray Industries (I picked up this tidbit from Darcy Brockbank who is a reputable nihonto dealer in Canada). This ensures a solid and even coat of oil.

Now let's talk about oil. Only relevant thing here is use GOOD oil. It can be high quality choji oil (I use Bob Benson's stuff but Okamura is another good supplier of high quality oil). It can also be good quality light mineral oil or sewing machine oil. The important part is purity and lack of other chemicals or distillates.

Wipe a nice even and light coating of oil on the blade and you're done.

Microfiber, isopropyl alcohol and good oil will keep your nihonto preserved, and won't damage the polish.

Stay away from silicone cloths or wax. Because these may hamper future polishes. I myself have dealt with the pain of stones not properly biting because a blade was treated with silicone or renaissance wax. For modern swords, this is fine. But for a nihonto there is a responsibility to care for it in advance of future generations not just caring for it during your own!

Feel free to discuss but this is my sage advice having dealt with nihonto for quite some time now.