Most antique nihonto do not need polishing. If your blade has minor surface scratches, a healthy shine, and a clearly visible hamon, leave it alone. Unnecessary polishing removes steel permanently and can destroy the very features that make a sword valuable.
A full polish by a qualified togishi in Japan takes 100 to 200 or more hours of hand work and costs roughly $350 to $1,400 for standard work. A pre-NBTHK shinsa quality polish runs $2,000 to $5,000 or more. These prices reflect a skill that takes over a decade to develop.
The critical warning: bad polishing is permanent damage. An antique nihonto polished by an unqualified hand can lose 30 to 50 percent of its market value overnight, with no way to reverse the loss.
Our recommendation: browse our authenticated nihonto, all in proper polish condition.
Last year, a collector in Melbourne contacted us in a panic. He had just acquired a Shinto-period katana with a genuinely beautiful hamon, some light surface haze, and minor handling scratches. A local polisher quoted him $800 and promised the work in a week. Here is why that almost went catastrophically wrong.
The polisher in question was skilled with Western blades. He had polished hunting knives, kitchen knives, even some European antiques. But nihonto polishing is an entirely separate discipline, with its own tools, its own sequence of work, and a learning curve that professional togishi in Japan spend over a decade mastering. That $800 quote would likely have cost the collector $6,000 to $10,000 in lost value, assuming the blade survived at all.
What Is a Togishi and How Is Sword Polishing Different from Sword Making?
A togishi (研師) is a professional sword polisher. This is not the same person as the swordsmith. In Japan, the two crafts are completely separate disciplines with separate apprenticeships, separate licensing paths, and separate professional organizations. A swordsmith forges the blade. A togishi reveals it.
Becoming a competent togishi requires a minimum of ten years of formal apprenticeship, and many practitioners consider fifteen years the real threshold for working on high-grade antiques. The training is hands-on and closely supervised. A student works through hundreds of blades under a master before being trusted with anything of real value.
The tools themselves are unlike anything in Western knife sharpening. A togishi uses a progression of specialized whetstones, most sourced from specific quarries in Japan, to work through successive stages of the polish. The final stages use hazuya and jizuya, small finger stones made from carefully prepared natural stone flakes, applied with direct hand pressure in precise patterns. The togishi is not just removing metal. They are managing the differential between the hard edge steel (ha) and the softer body steel (ji), bringing out the jihada grain pattern, and clarifying the hamon temper line without flattening or blurring either.
For a deeper look at what makes the hamon visible and how it forms, see our guide to hamon, nie, nioi, and the science behind the temper line.
How Do You Know If Your Nihonto Needs Professional Polishing?
This is the most important question a collector can ask, and the honest answer is: probably not.
Signs your nihonto does NOT need polishing
Minor handling scratches on the ji surface are normal on any blade that has been owned and handled. They do not require a full polish. If the hamon is clearly visible, the surface has a healthy shine when light catches it properly, and there is no active rust, your blade is in collector-grade condition. Leave it alone. Clean and oil it correctly, store it properly, and it will remain stable for decades. Our guide on how to care for an authentic nihonto: cleaning, oiling, and storage covers the maintenance routine in detail.
Signs your nihonto DOES need professional polishing
Active rust is the clearest signal. If you see orange or reddish rust forming on the surface, especially pitting rust that is eating into the steel, this requires professional intervention. Similarly, if the hamon has become obscured by a deep haze that oil and careful cleaning cannot clear, the surface needs work. Chips on the edge, deep pitting, or a blade that has been improperly cleaned or polished previously (flat, glassy surface with no jihada visible) are all genuine reasons to seek a togishi.
The jihada, the grain pattern visible in the body of the blade, is one of the primary markers of a blade's quality and authenticity. If it has been polished out, that loss is permanent. Our article on what is jihada and how to read the grain pattern in antique nihonto explains what to look for and why it matters.
What Does the Japanese Sword Polishing Process Actually Involve?
A full polish on a nihonto is divided into two main phases: nugui and shiage.
Nugui: the foundation work
Nugui is the rough correction phase. The togishi works through a series of progressively finer whetstones, establishing the geometry of the blade: the shinogi ridge, the boshi at the tip, the curvature, and the cross-section profile. This phase removes old scratches and oxidation but also removes steel. A blade polished too many times over centuries can lose geometry permanently. This is why unnecessary polishing shortens a sword's life and potential future value.
Shiage: the finishing work
Shiage is where the blade's character emerges. The togishi uses hazuya finger stones on the ji surface and jizuya stones on the ha area, working in specific directional patterns to bring out the jihada and clarify the hamon. This phase can take 50 to 100 hours on its own for a single katana. The result, on a well-executed shiage, is a surface where the steel's crystalline structure becomes readable: the swirling or flowing jihada grain pattern catches the light, and the hamon boundary shows its activity in nie and nioi with precision.
Total hours for a full professional polish on a standard katana: 100 to 200 or more. For a blade being prepared for NBTHK Tokubetsu Hozon or Juyo Token shinsa, the togishi may spend even longer, because the standard of work required for those certificates is exceptionally high.
How Much Does Japanese Sword Polishing Cost in Japan?
Prices below reflect qualified, licensed togishi work in Japan. These are the numbers you should use as your baseline.
| Type of Polish | Cost (USD approximate) | Notes |
|---|---|---|
| Standard polish, katana (qualified togishi) | $350 to $1,400+ | ¥50,000 to ¥200,000+; varies by condition and togishi reputation |
| Pre-NBTHK shinsa quality polish | $2,000 to $5,000+ | Required for Tokubetsu Hozon or Juyo Token submission |
| Antique blade in poor condition (heavy pitting, previous bad polish) | $1,400 to $3,000+ | Extra time for correction work; outcome not guaranteed |
| Wakizashi or tanto | $250 to $900 | Shorter blade, proportionally less time |
To put these costs in context against the value of the blades themselves: a Koto-period antique with NBTHK Hozon certification typically sells for $5,000 to $15,000. A Tokubetsu Hozon Koto blade runs $15,000 to $50,000. A Shinto-period blade with Hozon sits in the $4,000 to $12,000 range. A polish that costs $1,000 on a $6,000 blade is a significant investment, and a bad $800 polish can drop that same blade to $3,000 or less.
Waiting lists for top togishi in Japan routinely run two to five years. That one-week turnaround quoted to our Melbourne collector was the first red flag.
Understanding how NBTHK certification affects value and what the different certificate grades mean is worth knowing before you make any polishing decision. Our guide to NBTHK certificates explained covers each level in detail.
Can You Polish a Nihonto Outside Japan?
Yes, but the options are extremely limited and require careful vetting.
There are a handful of Western-trained togishi in the United States and Europe who have completed full apprenticeships under Japanese masters and are qualified to work on antique nihonto. We are talking about a very small number: perhaps ten to twenty individuals in all of North America and Europe combined who meet that standard. Some of them are excellent.
The problem is that for every qualified Western togishi, there are dozens of people offering "Japanese sword polishing" who have learned from videos, Western sword polishing techniques, or incomplete informal training. These practitioners may produce a blade that looks shiny and clean in photographs, but has had its jihada polished flat, its hamon boundary blurred, or its geometry altered. That damage is irreversible.
How to find a qualified togishi outside Japan: ask for specific references from Japanese sword collectors who have used their work, ask which Japanese master they trained under and for how long, and ask to see before-and-after images of antique nihonto work reviewed by someone who can read jihada and hamon. The Japanese Sword Society of the United States (JSSUS) and regional nihonto study groups are good starting points for referrals.
For most collectors outside Japan with a blade that genuinely needs polishing, the best path is shipping to Japan through an established intermediary. We assist collectors with this process for blades sourced through us.
Should You Use Uchiko on an Antique Nihonto?
Uchiko (打粉) is a traditional maintenance tool: a small ball of silk or paper containing fine stone powder, used by tapping lightly on the blade surface to remove old oil before re-oiling. You will find it in most traditional nihonto maintenance kits, and it has been used for centuries.
The debate today, particularly among NBTHK advisors and serious collectors, is whether uchiko is appropriate for high-grade antique blades. The powder is mildly abrasive. Over repeated use, it can gradually dull the polish surface on a fine shiage finish, and on blades with very active nie in the hamon, it may affect surface definition over time.
The current advisory position from conservative collectors and some NBTHK-affiliated experts: avoid uchiko on antique nihonto in a good polish, particularly on Juyo Token or Tokubetsu Hozon class blades. Use soft paper (oshi-gami or similar) and a light oil like choji oil for routine maintenance instead. Uchiko remains useful for more modern blades or training swords where preserving a fine shiage surface is not the priority.
If you are unsure what maintenance routine your specific blade requires, treat it as a case where less is more, and consult before acting.
How Does Polishing Affect a Nihonto's Value?
Polish condition is one of the primary factors determining a nihonto's market value. This is not a minor consideration: it is often the difference between a blade being collectible and being essentially unsaleable to a serious buyer.
A blade in a proper togishi polish, with clear jihada, a well-defined hamon, and correct geometry, commands full market value. The same blade after an inappropriate polish can lose 30 to 50 percent of that value immediately. In some cases, particularly with rare Koto blades where the original surface was part of the scholarly record, the damage affects academic as well as monetary value.
Polishing can also increase value, but only under specific conditions. A blade that is genuinely obscured by rust or haze, whose quality cannot currently be assessed, may be worth more after a proper polish reveals what it actually is. A blade with a certificate obtained after a previous polish may warrant re-polishing before resubmission if the current polish is degraded. These decisions require real expertise and should involve the togishi, a dealer who handles nihonto regularly, and sometimes an NBTHK advisor before work begins.
If you are thinking about polishing as an investment strategy, the numbers rarely work out positively. The cost of a quality polish ($350 to $1,400+, or $2,000 to $5,000+ for shinsa-grade work) plus the risk of value loss from even minor misjudgments means that polishing should be driven by the blade's condition needs, not by an attempt to increase market price. For more on what actually drives nihonto value over time, see our guide on nihonto investment: what determines if a sword holds value.
The safest position for a new collector is to buy blades already in proper polish condition, from sources that have done that assessment work for you. Browse our authenticated Japanese katana collection, where every blade has been examined and confirmed in appropriate condition before listing.
Every nihonto in our collection has been personally examined and confirmed in proper polish condition before it reaches you. No guesswork, no unpleasant surprises after purchase.
Browse Our Authenticated Nihonto Collection →Frequently Asked Questions
How much does it cost to polish a nihonto in Japan?
A standard katana polish by a qualified togishi in Japan costs roughly $350 to $1,400 (¥50,000 to ¥200,000+), depending on the blade's condition and the polisher's reputation. A pre-NBTHK shinsa quality polish runs $2,000 to $5,000 or more. Waiting lists for top togishi can extend two to five years.
Can I polish my own katana at home?
No. Nihonto polishing requires 10+ years of professional apprenticeship, specialized Japanese whetstones, and a trained understanding of jihada and hamon. Home polishing with conventional tools destroys the surface permanently and eliminates collector value. Even experienced knife sharpeners should not attempt this without proper nihonto-specific training.
How do I know if my nihonto needs polishing?
Your blade needs polishing if it has active rust, deep pitting, chips on the edge, or a hamon so obscured by haze that careful cleaning and oiling cannot clear it. Minor surface scratches, slight handling marks, and a blade with a clear visible hamon do not require professional polishing.
What is a togishi and how do I find one?
A togishi (研師) is a professional sword polisher, a separate specialist from the swordsmith, trained for 10+ years under a master. Outside Japan, only a handful are qualified to work on antique nihonto. Ask for references from nihonto collectors, verify their training lineage, and consult the Japanese Sword Society of the United States (JSSUS) or regional nihonto study groups for referrals.
Does polishing a nihonto increase or decrease its value?
Inappropriate polishing decreases value by 30 to 50 percent, permanently. A proper polish by a qualified togishi on a blade that genuinely needs it can restore or clarify value. Polishing a blade that does not need it always causes net loss. Condition assessment before any decision is essential.
What is uchiko and should I use it on an antique sword?
Uchiko (打粉) is a traditional abrasive powder ball used to remove old oil before re-oiling a blade. For antique nihonto in a fine polish, many NBTHK advisors now recommend avoiding uchiko, as repeated use can dull the surface over time. Use soft paper and choji oil for routine maintenance on high-grade antiques instead.
How long does a full professional sword polish take?
A full polish on a standard katana takes 100 to 200 or more hours of hand work by a professional togishi. A pre-shinsa quality polish for NBTHK submission may take longer. This is why quality polish costs what it does, and why any quote promising fast turnaround is a serious warning sign.
Key Takeaways
- Most antique nihonto in stable condition do not need polishing. If the hamon is visible and there is no active rust or pitting, proper maintenance through correct cleaning, oiling, and storage is the right approach, not a polish.
- A qualified togishi trains for 10 or more years and is a separate professional from a swordsmith. Outside Japan, only a very small number of practitioners have the training to work on antique nihonto without causing damage. Vet any polisher carefully and demand references before trusting them with a blade.
- Bad polishing destroys jihada and hamon definition permanently and can cost a collector 30 to 50 percent of a blade's value. Understanding what jihada and hamon are and why they matter is foundational knowledge before making any polishing decision.
- If you want to collect nihonto without taking on the risk of condition assessment and polish decisions, buy from dealers who have already done that work. Every blade in our authenticated nihonto collection has been personally examined before listing, and we are available to advise on any polishing questions for blades you already own.
View our current nihonto collection, all in proper polish condition →