Japanese sword sharpening
A Japanese swords guide on how to sharpen a Japanese sword
In Japan, sword-making was a sacred craft of mountain monks. The work later on was handed to blacksmithing families where the secrets of forging and alchemy were transmitted generation to generation.
For this divine task the smith garbed a priestly vestment, cleansed his soul with purifying water, and prayed to the gods for his success. The smith hardly worked alone however. He shared his duty with sharpener, the task of forging the blade equally delicate as polishing and sharpening it.
Togishi: Japanese swords sharpener today
The togishi, the polisher or sharpener, is proficient in the art and science of refining the final appearance of swords. Prodigious grasp of Japan’s culture, art, tradition, and history is necessary to accurately polish any blade according to its school, period, and style.
The job of the togishi is two-fold: either he restores a beat up sword back to its former luster or he sharpens a newly forged blade.
To sharpen or not to sharpen? That’s the question
It is of course satisfying to sharpen your own samurai swords. In that way, you can participate in the ancient art of bladesmithing and steelwork. If any of your collection has become chipped or rusted, it would do so much better to polish it back to glory.
However, experts will not recommend that you personally sharpen your collection of ancient samurai swords. You may end up doing more harm than good, and here’s why:
• Samurai swords are, first and foremost, swords designed to cut flesh. By sharpening, you need to handle the blade in ways you may not be prepared to do. A wrong finger on the razor-sharp edge is an accident waiting to happen. If you get yourself cut blood can cause rust and further damage to the sword, not to mention what it does to your finger.
• Samurai swords are works of art. There is no point risking their value by practicing your sharpening skills on them. Wheels, whetstones, exotic oils, paper-thin pebbles or special sandpapers are not enough without the deft, skilled hands of a professional togishi.
• Samurai swords have parts that are better be left untouched. The tang (nakago) is especially important for identification. Any swabs of acids and oils can erase the markings on the tang, making identification impossible, and—hold your breath!—wiping away half of the sword’s price tag.
• Samurai swords are sensitive to human skin. Any contact can potentially become stains and rusts on the blade. Handle the sword with a piece of a clean white cloth. Do not use colored fabrics; again, possible ugly stains may develop.
• Samurai swords have the best geometric and balanced shape, making them a perfection of steelwork and artwork rolled into one. Katana sword sharpening, which requires reshaping it, can result to irreparable structural deformities that can either devalue or weaken the sword.
Is it okay to sharpen modern Japanese sword?
Two things you need to bear in mind about modern Japanese swords: Mukansa and mass-produced. Mukansa is the art of katana blacksmithing following age-old tradition.
Today the NBTHK (Nippon Bijutsu Token Hozo Kyokai or the Sword Preservation Group) is the leading organization of samurai sword artisans following Mukansa tradition duly recognized by the Japanese government.
Clearly it is not recommended to sharpen the swords of NBTHK members, since the modern Mukansa mirrors that of the ancient sword-making. Please read antique Japanese sword for more discussion.
On the other hand, you can sharpen Japanese swords produced by manufacturing companies not sanctioned by NBTHK. Swords by Marto (or Martespa of Spain), Paul Chen swords from Hanwei, and CAS Iberia from Philippines can be polished. Most of these swords are meant to be beaters; that is, they are designed to be used for actual testing and therefore, sharpening.
Before you get started
There are two stages in sharpening katana swords: shitaji togi and shiagi togi. Shitaji togi or foundation polishing aims to remove unwanted grooves and to refine the overall shape of the sword.
The sword is to be brushed over a stationary stone. Any new swords have to undergo this stage, but older ones can get started to next stage. The shiagi togi or finish polishing aims to even out the surface and to finally produce the shiny gloss. Fine stones with tiny grits are moved over the blade this time.
Things you need to know
Here is a list of things you need to have.
• SHARPENING KIT You can buy one at any online store or specialty shops in your locality. Usually they contain several whetstones, polishing oil, hammer, cloth ball, and wooden jigs. A manual is also included to provide step-by-step instruction.
• GRIT is a measure of the abrasives on the sandpaper, stones, or other polishing materials. English scale is measured in particle size (microns). Take note that the Japanese grit differs from the US grit. So be careful, select only water stones and sandpapers for polishing which are measured against Japanese grit standard.
• SANDPAPER is made from coarse to fine grits as the polishing progresses. A favorite choice among polishers is silicon carbide abrasive paper.
• JAPANESE WATER STONES can either be natural or artificial. Natural water stones are difficult to acquire and if they are obtained, they are expensive. Artificial water stones are the substitutes, only that the results would vary. The stones have be to wetted before sharpening and when they become concave for constant friction, they have to be restored to shape by rubbing them with other stones.
• JIGS are wooden contraptions that can keep your work stable and steady.
• OIL would be helpful to keep off dust and rust from the blade while working. It will also keep the sword’s surface to be with the right moisture for polishing.
Now the real job: Sharpening sword 101
The first thing that you have to do is to buy sharpening kit. All the things that you may need are already included in the package, so you do not have to go to far lengths in procuring everything. However, you need to invest on Japanese water stones of increasingly finer grits to get your job perfectly. After that, proceed to the following steps:
1. Soak the stones. Japanese water stones are to be wetted before they can be used. Neutralize the acidity of the water first by sprinkling baking soda (about a fourth of the cup will do). The stones are to be soaked for around half an hour.
2. Shape the stones. The ideal shape of the stones is convex, but by constant friction it becomes concave. You need to reshape them back by scraping a stone against another of a coarser grit.
3. Prepare the wooden jigs. Some sharpeners can do the job standing, others sitting down. There are some who do it comfortably squatting. Whatever your most comfortable position is, make sure the wooden jigs would hold the sword and stones strongly.
4. Remove the blade from the scabbard and hilt. Do not rush by pulling things apart haphazardly. You might not be able to piece everything back together after you are done polishing. Do not unravel the leather wrap; it is done in a way so intricate that it would not be easy to wound it back again.
5. Straighten the blade. This is a difficult task because you need to have a good sense of geometry to get it right. Just remember that Japanese blade surface should be rigidly straight and not bent, curving gracefully from the base of the tang to the point. You can straighten the blade by placing the sword on your knee and forcing both ends downward. Use the wooden jigs for more ways to straighten it.
6. Sharpening. You are now on the first stage, the shitaji togi. Use arato stone (of a Japanese grit 180), secure it on the floor, and grind the sword against it. Grind deliberately, slowly, and carefully.
7. More Japanese water stones. Use stones of less coarse grits in the following order: binsui stone (of grit 300) to remove rust, kaisei stone (of grit 500) for finer shape, chu-nagura stone (of grit 800) for refining shape, koma-nagura stone (of grit 1500), and uchigumori stone (of grit 4000). It takes smart guesses and estimation when to use the stones, so it is better to read more information and follow instructional steps carefully to guide you through.
8. Now the second stage, the fine polishing. You are now in shiage togi for finer polishing. Prepare the stones for this stage by hacking paper-thin sizes from uchigumori stone to produce hazuya stones. Create the polishing powder called nugui powder (either the kit includes this detail or you have to produce your own). The nugui powder is very fine and it includes pulverized narutaki stones, tsushima stone, iron ore, etc.
9. Polishing. Unlike in the first stage, the stones have to move against the sword. Use your thumb in polishing the edge of the sword with hazuya stones.
10. When the tempering line is visible, use the jizuya stone. You can also use sandpaper of the grit 6000.
11. Use nugui powder. Mix nugui powder with sharpening oil. Moisten a swab of cotton or cloth with the oil and polish the surface of the blade.
12. Polish the cutting edge by hazuya stone to reveal the temper line (hamon).
13. For the mirror finish, you need to have steel needles, horn powders, and wax ball. Use the horn powder to wet the surface and run the wax ball to smoothen it. Carefully scratch the surface of the blade with the steel needles to see the gloss effect.
14. Finish the job by dabbing a white clean cloth over the blade. Remove all moist by letting in air throughout the blade’s surface. Once done, you can refit the sword back to the hilt and the scabbard.
The instructions here must be supplemented by expert guidance and comprehensive research. This is not a detailed guide on Japanese sword sharpening and must be read as a basic overview of polishing. When in doubt, please refrain from proceeding to any steps. It is best to hear what the professionals say about the condition of your sword before doing anything.
Sword care and maintenance
Samurai warriors went to great lengths to look after the condition of their swords. In the past, anyone who knocked down a katana sword on display or who carelessly handled it could be fighting a death match. You should take care of your ancient samurai sword—see the article sword care and maintenance—but let sharpening be the duty of the experts.