Learn how to sharpen katana blade
For ancient smiths katana sword was not only a matter of forging, but it was also a matter of sharpening. Sengo Muramasa in 16th century was considered the best Japanese sword sharpener in his time, his blades attaining mythical status for their otherworldly sharpness.
At that time, katana blades were rumored to contain an unremitting evil. In order to contain the anger of the evil, the samurai soldiers believed that they had to kill somebody before their katana was returned to its scabbard.
There were also stories of wielders forced to commit suicide if their katana were not able to kill or injure enemies.
Togishi: the katana blade polisher
In the history of katana, ancient polishers called togishi were respected in equal prestige with great swords smiths like Masamune. An inept polisher might destroy the most exquisite blades, while a master can produce stunning swords out of the dullest blades.
Polishing katana is an important task in producing the final appearance and beauty of the blade by correcting its imperfections such as wavy metal construction.
Antique katana sharpening
It is highly important to identify the type of the katana sword before it is sharpened. There have been stories of expensive, rare swords that were ruined by improper sharpening. Injuries caused by weak, snapping blades due to vigorous grinding have also been recorded.
Very old katana swords that are considered National Treasures of Japan are not anymore sharpened. This is because their chips and deformity are considered highly historical. Besides, there is a risk that these precious antique Japanese swords might get deformed in the process of sharpening.
Mukansa katana sword sharpening
Mukansa swords are original katanas produced by modern smiths duly licensed by Japan’s Agency for Cultural Affairs. These Japanese swords are forged according to the ancient tradition of katana making.
The Mukansa swords are valued for its artistry and appearance. They are most often bought by investors and serious sword collectors. Because Mukansa swords are valuable, their sharpening is left to the hands of professional, duly certified polisher.
Shinken katana sword sharpening
The shinken or battle ready swords, on the other hand, are made by manufacturers not licensed by the Japanese government.
They are mass-produced and therefore more affordable and easier to acquire than Mukansa swords. They are suitable for katana training in Japanese sword cutting techniques.
How to sharpen shinken katana
It is necessary to sharpen shinken katanas that has been dulled by frequent cutting practices. Here are the simple steps on how to sharpen katana blade:
1.) It is highly recommended to buy straightening and sharpening kits from reputable dealers. They contain instructional manuals to assist you. They also have important tools and materials like whetstones, sharpening oil, wooden jigs, sanding paper, and special wiping cloth.
2.) If kits are costly for you, you can procure the materials yourself: sandpaper of grits 80, 600, 800, 1500, 4000 and 6000; water; bucket; and clean white cloth. You can buy these sandpapers from your local hardware store.
3.) Remove the katana blade from its furnishings such as hilt, guard, and pommel.
4.) Immerse the blade in water for half an hour.
5.) Remove the blade from the water and start grinding it with the appropriate sandpaper. Use the 80 grit sandpaper for katana that are really in bad shape, and the 600 grit sandpaper for good but blunt swords.
6.) Grind from the fuller down to the cutting edge. Remember that Japanese sword has a sloping geometry, so your grinding pattern must only be downward.
7.) Be careful to observe an angle while sharpening. Maintain such angle all the time.
8.) By grinding, you should remove rust and grime in order clean the surface of the blade.
9.) As the shiny finish of the blade’s surface is slowly appearing, proceed to Japanese sword polishing. Use the sandpapers in the following order of grits: 800, 1500 and 4000.
10.) When the desired surface shine is achieved and the tempering line is visible, use the sandpaper of grit 6000 to polish the bevel of the katana until the cutting edge is revealed.
Final note: Please do not attempt to sharpen Japanese ornamental swords that are not made by Mukansa smith. They might be very weak structurally and susceptible to breaking when your grind them.