Uchiko Powder, Large

Uchiko Powder, Large. Imported from Japan.

Uchiko (打粉) is a fine polishing powder used in the maintenance of Japanese swords. It is most famous for being the "ball on a stick" (the Uchiko-dama) that you see people tapping against a blade.

While it looks like a simple cleaning tool, it is actually a byproduct of the sword-making process itself.

What is it made of?
Authentic uchiko is made from the crushed-up remains of high-quality Uchigumori whetstones. These are the specific natural stones used by professional sword polishers (Togishi) in the very final stages of polishing a blade.

The Process: The stone is ground into a powder and filtered dozens (sometimes hundreds) of times through silk or fine paper to ensure there is no grit that could deeply scratch the steel.

Modern Warning: Cheap cleaning kits often use talcum powder or calcium carbonate instead of real stone powder. While safer for beginners, these don't offer the same "polishing" benefits as the stone-based original.

What does it actually do?
Uchiko serves two primary purposes:

Degreasing: It is incredibly absorbent. It soaks up the old, dusty Choji oil so it can be wiped away cleanly with your Nugui-gami (the paper we discussed earlier).

Micro-Polishing: Because it is made of whetstone, it is a very mild abrasive. Tapping it onto the blade and wiping it off helps keep the steel bright and can help the Hamon (the temper line) stand out.

How to use it correctly
Using an uchiko ball is a specific ritual:

First Wipe: Use a clean piece of paper to wipe off the heavy layer of old oil.

The Tap: Hold the uchiko ball and gently tap it against the sides of the blade every 2–4 inches. It will leave small "puffs" of white powder.

The Polish: Use a fresh piece of Nugui-gami to wipe the powder along the length of the blade. This lifts the last of the oil and dirt.

The Inspection: Now that the blade is perfectly dry and clean, this is the best time to inspect the steel for flaws or beauty.

Re-oil: Crucial! Once you use uchiko, the blade is "naked" and will rust very quickly from the moisture in the air. You must apply a fresh, thin coat of Choji oil before putting it away.

Important: When NOT to use it
If you have an Iaito (an unsharpened practice sword made of aluminum or zinc alloy), do not use uchiko. The abrasive stone powder will eventually scratch or wear away the chrome plating. For alloy swords, a simple microfiber cloth and a tiny bit of oil (or even just glass cleaner) is usually enough.