The Secret World of the Japanese Swordsmith
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00:00Though only a small amount of metal, it is a weapon of great strength and elegance.
00:12Nor is it just a weapon, it is an instrument of which beauty is demanded.
00:17Within its calm serenity lurks a deep sadness, hidden by a mystical brilliance.
00:29Once born, each Japanese sword possesses a destiny.
00:34It must not break or bend, it must cut like a knife through butter.
00:40When samurai warriors donned their swords, they required them to look exquisite.
00:46A sword not only had the utility of a weapon, but also made a fine possession.
00:52The pursuit of these twin virtues gives the Japanese sword a unique and illustrious history.
01:14A samurai staked his life on his sword.
01:17From its origins over a thousand years ago to the present day,
01:21the Japanese sword is steeped in tradition.
01:24Down the ages, it has become the object of devoted study by many.
01:29Yoshindo Yoshihara, swordsmith, 54.
01:52Although there are many swordsmiths in Japan,
01:55Yoshindo is one of the few whose unique skills have gained him a following even overseas.
02:01He devotes himself to creating only the most beautiful swords.
02:08We will be seeing just how he goes about making a single sword.
02:12We will also learn just what the secrets are behind a sword that is strong and yet so pleasing to the eye.
02:19Yoshindo has never before revealed the secrets of his craft to the layman.
02:24Today, we will be allowed a glimpse into this mysterious art.
02:38The art of Japanese sword making reached its pinnacle at the beginning of the 13th century,
02:43during the Kamakura period.
02:45Modern swordsmiths aimed to emulate the incredibly high standards of those times.
02:51The secret of a Japanese sword's strength lies in its dual composition.
02:56It consists of a softer, more flexible core steel, known as shingane,
03:01swathed in a hard outer steel jacket, known as kawagane.
03:06This makes the sword superbly strong, difficult to break, and gives it an excellent cutting edge.
03:12The other key characteristic of Japanese swords is the use of a raw material known as tamahagane.
03:19This special kind of Japanese steel is made by heating satetsu, or iron sand,
03:24over charcoal at comparatively low temperatures, resulting in a steel that is low in impurities.
03:30Elsewhere in the world, steel from blast furnaces is used.
03:34In Japan, rather than using coats, the smelting of tamahagane is done using charcoal throughout.
03:40The swordsmith has to distinguish between the different pieces of steel
03:44and pick out carefully those best suited to making a sword.
03:50This is the smithy where swords are created.
03:57The setup is very simple.
03:59To the left of the forge is a piston-operated bellows.
04:03This pumps air into the forge to allow the temperature to be adjusted.
04:08These are the tools needed in making a sword.
04:18There are tools for grasping the steel,
04:22and others for hammering it.
04:28A special kind of pine charcoal is used to make the blade.
04:37Known as matsuzumi, it is used as a fuel for the forge
04:41because of its ability to produce a lot of heat.
04:46Yoshindo performs a traditional fire-lighting ceremony typical of a swordsmith.
04:51First, he hammers a plain iron rod down to a sharp point.
05:01When the tip of the rod is struck hard and fast,
05:04the point absorbs enough heat to be able to light a piece of paper.
05:08This kind of hammering technique is the starting point for Japanese sword-making.
05:21Using this flame, he lights the forge.
05:25Charcoal is added, and the forge soon begins to produce heat.
05:40Yoshindo places the tamahagane in the forge,
05:43the first step of making the kawagane steel jacket.
05:48Working the bellows, the smith pumps blasts of air into the forge.
05:52Adjusting the heat, he smelts the tamahagane.
05:57A single Japanese sword typically weighs between 750 and 950 grams.
06:02During the sword-making process,
06:04Yoshindo has to make the kawagane steel jacket,
06:07the first step of making the kawagane steel jacket.
06:10The first step of making the kawagane steel jacket
06:13is to make the kawagane steel jacket.
06:16The kawagane steel jacket is made of steel,
06:19and the kawagane steel jacket is made of metal.
06:23During the sword-making process,
06:26most of the raw material is removed as impurities.
06:29Therefore, around three or four times
06:32this quantity of tamahagane is used to make a katana.
06:38When the piece of tamahagane has become red-hot,
06:41Yoshindo pulls it out of the forge and holds it on the anvil,
06:45while his disciples hammer it flat using ten-kilo hammers.
06:52The hammering is repeated several times.
06:55With Yoshindo tapping out directions,
06:58the tamahagane is quickly made flat.
07:01During this process,
07:03the impurities within the steel rise to the surface,
07:06and the kawagane steel jacket is made.
07:09The kawagane steel jacket is made of steel,
07:12and the kawagane steel jacket is made of metal.
07:15The kawagane steel jacket is made of steel,
07:18and the kawagane steel jacket is made of metal.
07:21The metal rises to the surface and can be hammered out.
07:39Once the steel is about the same thickness as a cracker,
07:43the process known as mizuuchi is performed.
07:46Water is sprinkled underneath the steel wafer,
07:49and it is hammered once more.
07:51The combined effect of the steam and the shock induced by hammering
07:55causes the surface to peel off.
07:57Impurities disappear.
08:01This part of the operation,
08:03known as shita-goshirae, or foundation forging in Japanese,
08:07is critical for removing as many of the impurities as possible
08:11before proceeding to the next stage.
08:19Shita-goshirae
08:37When the steel is quenched in water, cooling it down quickly,
08:41it is made harder.
08:43The wafers of hardened tamahagane are broken into smaller pieces.
08:48At this stage, the carbon content of the steel is still too high.
08:52Although hard, the steel in its current state
08:55would make a sword weak and extremely brittle.
08:58The ushindo must once again select which of the small, thin,
09:02broken-up wafers of tamahagane are best suited to make the sword.
09:17Shita-goshirae
09:47Shita-goshirae
10:18Shita-goshirae
10:25Yoshindo makes a steel plate
10:27welded to a long handle out of tamahagane steel.
10:31Together these are known as the tekogane.
10:35Shita-goshirae
10:43All the operations are performed with barely a word spoken.
10:47The commands of the swordsmith's hammer is all that is required.
11:04Shita-goshirae
11:25In due course, the tekogane plate will itself become part of the sword.
11:35On top of it, Yoshindo stacks a pile of the selected tamahagane wafers,
11:41leaving no gaps in between the separate pieces.
11:50To make a sword strong and flexible,
11:53the steel must be completely uniform throughout the length of the blade.
11:57To achieve this, many layers are squeezed together in the forging process.
12:04Shita-goshirae
12:13Burning rice straw is another vital part of the whole operation.
12:17The black rice straw ashes, known as warabai,
12:21are wrapped around the steel during forging to prevent overheating,
12:25which would result in too great a loss of carbon.
12:28This makes them one of the secrets of sword creation.
12:34Shita-goshirae
12:43The steel wafers are skillfully arranged on top of the tekogane plate
12:47to make a block of steel.
12:50To prevent the wafers from spilling over, collapsing, or falling off,
12:54the smith carefully wraps the block with wetted Japanese paper.
13:05Yoshindo
13:09The black warabai ashes are coated onto the paper-wrapped bundle.
13:13This helps compensate for the loss of carbon that occurs with heating.
13:24Yoshindo now pours a clay and water mixture over the block.
13:29The clay and ash wrapping ensures that heat passes evenly through the block to its core.
13:35As the temperature of the block mostly rises from the inside out,
13:39this prevents carbon loss happening on the surface only.
13:43The result is a steel block which is uniform.
13:47The use of straw and the clay slurry is typically Japanese.
14:00Tsumi-wakashi
14:06The next step in the process is known as tsumi-wakashi in Japanese,
14:10which literally means piling up and boiling.
14:14Yoshindo places the steel block in the forge and heats it slowly,
14:18adjusting the air with the bellows.
14:21Since different temperatures act on various materials to produce different kinds of swords,
14:26the process demands a combination of intuition and experience.
14:39Peeping into the forge, he can see that the surface paper and ash wrappings have already melted.
14:45He does not want to melt the entire block of steel away.
14:49Sensing when the inside of the tamahagane block is almost boiling demands a high degree of skill.
15:19Tsumi-wakashi
15:49Once the layers of tamahagane have been compacted,
16:12the block is re-wrapped and placed in the forge once more.
16:20Tsumi-wakashi
16:24Tsumi-wakashi
16:38Tsumi-wakashi
16:53Tsumi-wakashi
17:23Tsumi-wakashi
17:26Tsumi-wakashi
17:44The rhythm of Yoshindo's small hammer tells his disciples wielding the large hammers
17:49how hard and fast they should hit the steel.
17:56Tsumi-wakashi
18:16In the next stage, a cut is chiseled into the block and the steel is folded back over itself,
18:22resulting in a new piece double the original thickness.
18:25This process is known as orikaeshi, or folding back in Japanese.
18:31Each time this is repeated, more impurities within the tamahagane,
18:36principally titanium, phosphorus and sulfur, are peeled or scraped off or scattered by the hammer blows.
18:44Each repeat also reduces the carbon content a fraction.
18:48To reach the correct level, the process needs to be repeated around a dozen times.
18:55The orikaeshi continues, and each time the new block is wrapped in ashes and coated in the clay slurry.
19:02Tsumi-wakashi
19:16The block is stretched by hammering to double its original length before folding.
19:21Tsumi-wakashi
19:26The first cut was made crosswise. The next cut is made lengthwise.
19:31Cutting this way in a cross formation is a matter of careful calculation.
19:36What is the purpose of it?
19:39Tsumi-wakashi
19:47Experimenting with this clay model illustrates the principles involved here.
19:52The flattened wafers of tamahagane all differ in their precise carbon content.
19:58Thus, when stacked, heated and then hammered, the parts meld and the whole gains even greater strength.
20:05Hundreds and thousands of thin steel layers pile up on top of one another and become enmeshed, creating a dense structure.
20:16With every repeat of orikaeshi, the number of layers doubles.
20:21After the tenth time, the steel consists of 1024 layers or more.
20:28After polishing of the final blade, these different layers show up in an exquisite surface pattern known as the sword's jihada.
20:37In the folding lies the secret to the sword's combination of strength and beauty.
20:45The swordsmith's individuality is strongly reflected in the interplay of colors and textures in the final sword.
20:53The jihada, in particular, is an important way of differentiating between the work of different craftsmen.
21:00The stage is now set for the smith to sever the steel from its tekogane handle.
21:30The hard, toughened steel is bent into a U-shape, which becomes the sword's outer casing, or jacket, the kawagane.
22:01Formed by a similar process, the slightly softer shingane forms the core of the sword and is inserted inside the jacket.
22:10Hardened steel is used for the cutting edge.
22:13The more flexible inside of the sword absorbs the shock of an attacking stroke.
22:19This use of harder and softer steels in Japanese swords distinguishes them from swords made elsewhere,
22:27which are made of a uniform steel throughout.
22:36The key point here is that the swordsmith assembles the different forged kawagane and shingane layers of the sword
22:43so that the grains of each run at right angles to one another.
22:49The precise way the kawagane and shingane combine leads to a myriad of different possibilities,
22:55producing swords of varying strength and movement.
22:59The beauty of the jihada truly reflects the skill of its creator.
23:19The initial forging is now complete.
23:23Yoshindo now moves on to shape the sword to his liking.
23:39The composite steel blank used as the basis for the sword, incorporating both the kawagane jacket and shingane,
23:47is known as the sunobe in Japanese.
23:51Yoshindo puts the combined bar into the forge, taking care not to heat it too much.
23:57He then hammers it into the rough shape of a sword, lengthening it as he goes.
24:03He has to be careful not to destroy the balance between the jacket and the core steels.
24:17By separating the sunobe from the tekogane rod, he creates the piece that will become the final sword.
24:48By this stage, practically all of the impurities have been beaten out of the tamahagane,
24:54leaving only about a third of the weight of the original material.
25:17Here Yoshindo forms the tip of the blade.
25:47He then hammers the tip of the blade into the shape of a kawagane jacket.
26:17He then hammers the tip of the blade into the shape of a kawagane jacket.
26:38He then hammers the tip of the blade into the shape of a kawagane jacket.
26:47He then hammers the tip of the blade into the shape of a kawagane jacket.
26:53He then hammers the tip of the blade into the shape of a kawagane jacket.
26:59He then hammers the tip of the blade into the shape of a kawagane jacket.
27:19The process of shaping the blade out of the sunobe and giving it curvature is known in Japanese as hizukuri.
27:28His disciples' assistance is necessary up until the formation of the sunobe,
27:33but hizukuri is the job of the swordsmith alone.
27:37He proceeds with a conceived shape in mind.
27:41This part of the process brings all his senses and technique to the fore.
27:58It is crucial at this stage to minimize the number of times the blade is heated up.
28:04Yoshindo must move with lightning speed to prevent any more carbon leeching out of the blade.
28:10Conserving the steel is a vital skill.
28:13The smith must prevent the sword from cooling or impurities from adulterating the sword.
28:19Producing an attractive jihada on a blade surface is a sign of fine craftsmanship.
28:49He then hammers the tip of the blade into the shape of a kawagane jacket.
29:19The actual curvature of the sword is not mentioned in the manual,
29:24but it is important to keep in mind that the curvature of the blade is not determined by the shape of the blade.
29:31The curvature of the blade is determined by the shape of the tip of the blade.
29:36The tip of the blade must be straight and the tip of the blade must be curved.
29:41The tip of the blade must be straight and the tip of the blade must be curved.
29:46The actual curvature of the sword is not manifest until later when the edge of the blade is hardened.
29:53This makes it very difficult to imagine exactly how curved it will turn out to be.
29:58The swordsmith must use his experience to determine his sword's final shape and thus its elegance.
30:07Once hizukuri is complete, you can begin to imagine the blade in all its final splendor.
30:28The shape of Japanese swords changed over the ages as methods of waging battle changed.
30:35These different styles and methods of use have all added to the complexity of the Japanese sword-making craft.
31:35Having used his hammer to shape the blade, Yoshindo now begins the finishing process.
31:49First he does a rough filing. This determines the blade's frame.
32:05He then uses a chisel to cut out the shape of the blade.
32:16He then uses a chisel to cut out the shape of the blade.
32:35This part of the process is finished with a whetstone.
33:05All surface oil is removed using an ash water solution, and the blade is then dried thoroughly.
33:35The smith now turns his attention to the single most important part of the blade, the hamon.
33:42This is the pattern created along the blade in its final quenching.
33:48Yoshindo's own particular specialty is a type of hamon called ochoji, or big-clothed hamon.
33:54It is a type of hamon that is used to create the shape of the blade.
34:00It is a type of hamon that is used to create the shape of the blade.
34:06Yoshindo's own particular specialty is a type of hamon called ochoji, or big-clothed hamon.
34:12A derivative of the clothed hamon patterning developed to perfection in the Kamakura period,
34:18this type of hamon is considered one of the most beautiful.
34:37To make a hamon with this wonderfully variable pattern, a special clay is used.
34:43The adhesive clay is made out of a mixture of charcoal, pulverized whetstone, and other ingredients.
34:49The exact proportions are the smith's own personal secret.
35:06Yoshindo's specialty is a type of hamon that is used to create the shape of the blade.
35:22Having carefully prepared the mixture, Yoshindo applies it to the roughly ground sword with equal delicacy.
35:30The clay is painted onto the blade in a thin layer.
35:34Once it is dry, it will be fired.
35:37The precise details of this process of making the hamon, called tsuchioki, or placing the clay in Japanese,
35:44have been a closely guarded secret of Japanese swordsmiths since time immemorial.
36:05Yoshindo now uses a thicker clay mixture to coat the remainder of the sword.
36:11This coating is to ensure that the blade does not heat up too much and overharden.
36:34TSUCHIOKI
37:05It is this process that brings out the hamon.
37:09Yoshindo makes his signature clove blossom pattern using a fine spatula to place the clay on the blade.
37:17A complex pattern of straight lines, crosses, and points will result in the wondrous clove blossom, or choji hamon.
37:35The tsuchioki process for the clove blossom hamon is now complete.
37:41Exactly how the hamon is created is still something of a mystery, however.
38:04This is a pattern for a relatively straight hamon, called suguha in Japanese.
38:11SUGUHA
38:29This hamon is known as the notare pattern and is famously attributed to the master swordsmith Kanemitsu Bizen.
38:37Its slightly irregular patterning gives it a peculiar beauty all of its own.
39:07KANEMITSU
39:23Finally, we come to the yaki-ide process of hardening the edge.
39:28This is where the sword's underlying elegance is brought out in an instant.
39:34Small pieces of matsuzumi charcoal are used to ensure the clay coating does not peel off.
39:41Yoshindo takes great care to ensure the heat of the forge is as even as possible.
40:04YAKI-IDE
40:10Because he must be able to distinguish very subtle changes in the color of the hot sword,
40:15Yoshindo performs yaki-ide in pitch blackness.
40:23Carefully passing the sword through the forge with one hand, he pumps air into the forge.
40:28Each push of the piston changes the forge temperature, and this has to be judged by the color of the sword.
40:35Maintaining the temperature between 725 and 780 degrees Celsius,
40:40Yoshindo ensures that the sword is heated evenly all around.
40:53Then he quenches the sword suddenly in a trough of water.
40:57This dramatic cooling, owing to the peculiar properties of steel,
41:01produces a different crystalline microstructure at the edge of the blade called martensite,
41:06which is particularly hard.
41:27Yoshindo lightly passes the blade through the forge a second time.
41:48Next he tempers it by quenching again.
41:51This relieves stress in the hardened edge and ensures the entire blade remains flexible and strong.
42:00After yaki-ide, the curvature of the sword has increased slightly.
42:22After further treatment to clean off the clay, we reach the crucial moment when the hamon is revealed.
42:29The clove blossom line should be very clearly visible on the blade.
42:34At this point, Yoshindo can tell whether yaki-ide has been a success or not.
42:51There are many differences in the width of the blade.
42:56The width of the blade is 70% wider than the original width.
43:06The thickness of the blade is 70% wider than the original width.
43:16The thickness of the blade is 70% wider than the original width.
43:35The blade's tang, called nakago in Japanese,
43:39is the part of the sword where the swordsmith carves out his signature marks.
43:46The nakagoyana, or rivet hole, is drilled into the tang for the rivet that will secure the blade to the hilt of the scabbard.
43:53This helps improve the sword's balance.
43:58The nakago, or rivet hole, is the part of the sword where the swordsmith carves out his signature marks.
44:03The nakago, or rivet hole, is drilled into the tang for the rivet that will secure the blade to the hilt of the scabbard.
44:12This helps improve the sword's balance.
44:22The job of the polisher is to bring out the smith's intended hamon and make the jihada look as good as possible.
44:29He helps to breathe life into the sword and bring it to its final state of sparkling brilliance.
44:41He helps to breathe life into the sword and bring it to its final state of sparkling brilliance.
44:53Inscription marks often include the swordsmith's name, the date of creation, and the name of the person who ordered the sword.
45:11The Japanese sword can be thought of having arisen out of the natural desire of every warrior to wield a marvelous weapon in battle.
45:41The cherry blossoms enshroud the seated samurai.
45:46The grace with which they fall mirrors the warrior's spirit.
45:51Since ancient times, the Japanese have revered both the samurai and the cherry blossoms as the ultimate in grace and refinement.
46:12Today, the Japanese sword is also held up as an example of exquisite artistry and craftsmanship.
46:19In ancient times, we know that it was used as a potent weapon.
46:29Here, mimicking the samurai of old preparing themselves for a battle, the warrior roughens the edge of the blade slightly on a whetstone.
46:38This gives the sword an added sharpness.
46:46Sword making requires daring and delicacy.
46:51The crafted sword concentrates in its fine lines the knowledge of the ages mixed with a sense of omnipotence.
46:58As he polishes the blade, the polisher is aware that he is in fact wearing away the life of the katana in his hands.
47:07In the act of creation, he is locked in a battle with his fellow artisans, engaging in the sword play of the smith.
47:38It is not enough merely to cherish the beauty of a Japanese sword.
47:44It is a weapon in which one entrusts one's life.
47:48It is naturally drawn to the battlefield.
47:51Once there, the warrior must wield it resolutely to kill if necessary.
47:57If he falls, he falls gracefully.
48:02It is perhaps impossible to touch the real, secret beauty of a Japanese sword
48:07until one comprehends the spirit of the samurai and the solemn Bushido oath he bears in his heart.
48:31Thank you for watching!