How Should I Clean a Samurai Sword

A katana is not only a symbol of Japan but also a superb piece of art and cultural heritage. Each katana carries rich historical and incomparable craft values, thus its maintenance and cleaning surpass that of ordinary metal items. Proper care can extend the life of a katana and maintain its historical and aesthetic characteristics. This article will detail how to professionally and cautiously clean and maintain a katana, ensuring each sword receives the most suitable treatment, while also providing key safety and protective measures to avoid damage to the blade or the operator during cleaning.

Materials Required for Cleaning a Katana:
Choji Oil

A special oil blend made from mineral oil and clove oil, choji oil is typically transparent or slightly yellow with a distinctive clove scent. It is primarily used for rust prevention and blade protection, with the clove oil component providing mild antiseptic and antibacterial effects. To use, apply a small amount of choji oil evenly on the blade using a soft cloth, ensuring the oil covers the entire blade but not excessively to avoid oil build-up.

Uchiko Ball

Consisting of a wooden handle and a rounded head wrapped in fine silk cloth filled with fine stone powder, the uchiko ball serves as a gentle abrasive tool. It removes minor scratches and stains from the blade while polishing it. Lightly tap the uchiko ball on the blade, sweeping from the hilt to the tip, allowing the fine stone powder to spread evenly and absorb oil and impurities. After use, wipe off the stone powder with clean nuguigami paper.


An extremely soft, non-woven special paper, nuguigami is delicate, durable, and lint-free. It is used during the katana cleaning process to wipe oil, dust, and other impurities, protecting the blade from scratches. Nuguigami should be used both before and after other cleaning steps, especially after using the uchiko ball to remove stone powder and after applying choji oil to remove excess oil.

Katana Cleaning Steps

Step 1: Initial Preparation and Inspection

Before starting the cleaning process, ensure a clean, spacious, and well-lit work environment. Gently remove the katana from its scabbard, keeping the sharp edge up and the tip slightly tilted upward. Place the katana on a dust-free, non-lint producing soft cloth to prevent scratching the katana blade (Nagasa) or damaging the tip. Balance the blade to avoid any sudden movements that could damage the blade or cause accidental cuts. Carefully inspect the blade for rust, scratches, or other visible damage, which will determine the intensity of the cleaning needed. Tap lightly on the edge of the scabbard mouth (Koiguchi) to dislodge any small fragments or dust inside, a crucial step to prevent blade wear and corrosion.

Step 2: Preliminary Wiping with Nuguigami

Take a sheet of nuguigami, wrapping it gently around two fingers. Start near the hilt and slide towards the tip, gently wiping away surface dust and fingerprints. This step aims to remove larger impurities and surface oil, preparing for a deeper clean. If the blade has grooves (Bo-hi), use pinched nuguigami to carefully clean these areas to ensure all grooves are thoroughly cleaned. Ensure that only nuguigami comes into contact with the blade during this process to avoid new stains or accelerated corrosion from oils on the hands.

Step 3: Use Uchiko Ball to Remove Old Oil and Minor Scratches

Gently tap the uchiko ball on the blade, especially where there are visible old oil marks or light rust spots. The fine stone powder in the uchiko ball will help remove these stains through mild abrasion and provide some polishing. Start near the hilt and move toward the tip, ensuring every part is covered. Be careful to tap the uchiko ball evenly across the blade, avoiding excessive force in sensitive areas like the tip to prevent damage. If oil spots or fine scratches are found, repeat this process until satisfactory.

Step 4: Clean Again with Nuguigami

After using the uchiko ball, thoroughly clean the blade again with nuguigami to remove any remaining stone powder and particles produced during the polishing process.

Step 5: Apply Choji Oil to Protect the Blade

Take a small clean cloth, dip it in choji oil, and gently apply it across the entire blade. This oil layer aims to form a protective barrier against future oxidation and corrosion. After oiling, use fresh nuguigami to lightly wipe off excess oil, ensuring the oil film is even and not excessive to prevent oil accumulation attracting more dust.

Step 6: Remove Excess Choji Oil

Ensure no excess oil remains on the blade to prevent dust and impurities from adhering. Use fresh nuguigami to gently wipe off excess choji oil, especially checking areas like the Habaki and decorative seams to ensure no oil accumulation.

Step 7: Final Inspection and Storage

After completing all cleaning steps, perform a final inspection and safely place the katana back into its scabbard and display stand. Check the oil coating on the blade for uniformity, ensuring no areas are missed. Once satisfied with the cleaning and polishing results, carefully return the katana to its scabbard (Saya) and place it on the display stand.

Important Considerations During the Cleaning Process
Wear Appropriate Protective Gear

Gloves: Wearing gloves prevents direct contact with the sharp blade and avoids corrosion from oils and sweat on the hands.

Work Attire: Wearing appropriate work attire prevents clothing from being scratched, especially when handling large katanas.

Choose the Right Work Environment

Dry and Ventilated: Select a dry and well-ventilated environment for cleaning to prevent moisture-induced corrosion.

Well-lit: Ensure the work area is well-lit, which not only helps identify minor stains and damage on the blade but also ensures precision in operations.

Handle the Katana Properly

Avoid Rough Handling: Handle the katana gently when removing or returning it to prevent damage to the blade or scabbard.

Blade Direction: Always ensure the blade's direction is safe, avoiding pointing towards oneself or others, especially during polishing or oiling.

Use the Correct Cleaning Tools and Materials

Avoid Inappropriate Cleaners: Do not use corrosive chemical cleaners that could damage the blade and decorations.

Strictly Follow Guidelines for Specialized Tools: Use tools specifically designed for katana maintenance, such as the uchiko ball and nuguigami, to avoid materials that could scratch the blade.

Observe Carefully and Address Issues Promptly

Check for Corrosion and Rust: Promptly identify and address any corrosion or rust during the cleaning process to prevent further damage.

Double-check: After each step, carefully inspect the treated areas to ensure no omissions or unevenness.


Maintaining the cleanliness and care of a katana is a process that requires meticulous operation and strict attention to detail. From selecting the appropriate cleaning tools to ensuring operational safety, each step must be executed with care. The methods introduced in this article not only help maintain the functionality and beauty of the katana but also emphasize the importance of protecting these valuable art pieces. By following these professional cleaning steps and precautions, your katana will retain its historical value and glory, ensuring safety during operation.

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