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Chapter 2

Creating a Japanese Sword

The Japanese sword represents the quintessential instrument of warfare. Unlike similar weapons developed throughout time, the Japanese sword evolved to a degree of metallurgical sophistication unmatched the world over. Indeed, modern swordsmiths still experiment with various techniques in an effort to reproduce some of the subtle effects of medieval Japanese swords. Shining like stunningly unique gems, nihōntō have stirred innumerable people to devote lifetimes to their appreciation. The functionality, complexity, and visual beauty of these art pieces have inspired many areas of study. Volumes have been written on distinguishing minute but distinctive characteristics produced by different smiths and schools throughout history. A comprehensive study of all the sword-related crafts is beyond the scope of this text, however, a brief introduction to how swords are made will be useful in promoting their appreciation.

Producing a finished sword is not the work of the swordsmith alone. The process of manufacturing a nihōntō requires the collaboration of several independent and highly specialized artisans. Each undergoes a lengthy apprenticeship. Swordsmiths apprentice for five to seven years before receiving licensure. The sword polisher’s apprenticeship can last up to ten years, depending on the school and teacher, while the habaki maker trains for up to eight years before being able to stand on his own. Consequently, these are celebrated artisans; their work highly honored, scrutinized and sought-after. Small ornaments or figurines wrapped into the handle, called menūki, provide another example of the appreciated details of nihōntō. Each of these craftsmen strives to produce work with a technical perfection where visual composition, subtlety, and infinite attention to detail leave the viewer in awe.

The swordsmith and his apprentices mix, refine, fold and forge the steel into the blade. The smith then passes the blade to the polisher, or tōgishi, who carefully refines the surfaces and lines of the blade on various grades of waterstones. Once the basic geometry of the blade has been refined, the polisher sends the blade to the habaki maker. After the habaki has been made, the blade is transferred to a scabbard maker who will carve a scabbard to fit its exact measurements. Once the scabbard has been made, the blade goes back to the polisher for shiage-tōgi—the final polishing stages that meticulously bring out the hamon features and texture of the grain using the finest-grade stones. Only after receiving the blade back from these artisans will the swordsmith sign his name to the blade tang.

Apprentices are allowed to play a part in their master’s work according to their dedication and developed skills. Their efforts pay off in their growing ability to produce good works, and the honor that goes with a job well done. The beauty and genius of these trades emerge as we look deeper into the art and craft of the sword.

This chapter reflects my journeys to Japan and meetings with sword makers and polishers. I am very honored to have been welcomed into the workshops and homes of many top craftsmen. Two, in particular, have contributed much of their time, resources, and knowledge to this project. The first craftsman is Kawachi Kunihira, a 15^th generation sword maker in the mountains of Nara prefecture. The second craftsman, Abe Kazunori, is a sword polisher in Tōkyō. This chapter outlines the processes involved in creating a Japanese sword through their daily practices. In essence, they will act as our tour guides as we explore the creation of Japanese swords.

Carefully watching the fire and steel, the master smith and his apprentices await the perfect moment to work the glowing billet.

Both Mr. Kawachi and Mr. Abe have been declared mūkansa, or master craftsmen, a title awarded to artisans having received more than the prescribed number of Special Prizes at the yearly NBTHK competitions. Each has studied under the most famous teachers in Japan and holds a number of private and governmental honors. Yet, despite their highly specialized skill sets, each of these men would politely reject any compliment. They would assert that working with swords is just what they do. They are not holy-men, shamans, or priests, just hardworking craftsmen. Regardless of their humility, it is easy to appreciate their passion, exacting standards, and dedication to maintaining traditional arts.

Central to the Japanese swordsmiths’ craft is the ability to create a sword from a difficult raw material, combining various densities of steel into an ingenuous sword-structure. The resulting sword has durable outer layers combined with a soft core that is not easily broken. Known for their razor-sharp edge, elegant curve, and graceful steel patterns, the appreciation of nihōntō extends far beyond mere metallurgy or warfare. Yet it is the metallurgy and combat applications that make the Japanese sword so alluring.

Manufacture of Traditionally Smelted Steel

Historically, two processes have been used in the traditional manufacture of Japanese iron and steel. These two processes are referred to as zūkū-ōshi and kera-ōshi. The former closely resembles the “pig iron” (a type of cast-iron) produced in high-temperature furnaces, while the later is a type of low-fired sponge iron. The difference between them is that in the kera-ōshi process, the iron doesn’t liquefy, but rather agglutinates into one mass. When it comes out, it looks spongy—thus, the name “sponge iron.” Surprisingly, in Japan, it is thought that high-temperature zūkū-ōshi was the main technology of the Middle Ages, whereas kera-ōshi became dominant in later times, and remains popular today. This seems contrary to the chronological evolution of metallurgy in the West.

Today, the sword-steel tamahagane, one of the products of a kera-ōshi tatara, is jointly produced almost exclusively by a partnership involving Hitachi Metals, the Japanese government, and the NBTHK in Yokota, a small town in Shimane prefecture. In this process, iron ore contained within dark brown or black sand is smelted in a clay furnace, using charcoal as the fuel as well as reducing agent. The liberated iron then combines with more carbon to form steel alloys. Some swordsmiths operate their own tatara within the confines of their smithies and produce their own tamahagane. Producing tamahagane on such a small scale, however, is quite difficult and rare. Today, traditionally produced NBTHK tamahagane is chosen by many smiths; despite its high cost. It is important to note that some smiths use steel produced in ways other than from the NBTHK tatara.

Master sword polisher Abe Kazunori assesses a blade with careful consideration.

Broken chips of tamahagane can be stacked and forge-welded into a billet.

A painting showing a selection of tools used in the tatara for the creation of swords.

Iron-bearing sand is refined into sponge-iron, pieces of which can be stacked to form a billet.

Working with a steady, syncopated rhythm, the apprentices elongate and fold the steel during tanren.

Mr. Kawachi and his apprentices have just completed a fold and quickly work to weld the surfaces together.

These are pieces of re-smelted iron and steel for use in creating an oroshi-gane billet.

Once the billet has been forge-welded together it is folded repeatedly, creating layers within the steel.

Tamahagane is not the only type of raw material used in sword making. For example, ōrōshigane is a process that consists of re-smelting, in the smith’s own forge, various bits of iron, steel or cast iron in order to make them usable in sword making. Broken cast iron kettles, ancient temple hardware or farming tools are all acceptable sources for ōrōshigane. The process, depending on how it is performed, will increase or decrease the carbon content of the metal, and form it into a single lump. The end product is also referred to as ōrōshigane, as opposed to tamahagane.

Both the tamahagane and ōrōshigane aim to manipulate a symphony of delicate factors. Carefully controlling the carbon content, homogeneity, crystallinity, and other factors allows the raw steel to achieve the quality needed for sword steel. Some pieces of steel are unusable because of their excessively high or low carbon content, poor structure, and so on, and must be put aside. The smith may decide to re-smelt these odds and ends for a later project in ōrōshigane.

It must be understood that, except in rare cases, specialized craftsmen work alongside a few swordsmiths to manufacture sword steel at the NBTHK tatara. Together, they prepare the tamahagane for sword-making by smiths around Japan. Without the efforts and skills of the craftsmen at this early stage, there would be few nihōntō for us to appreciate today.

Refining the Steel By Forge-Folding (Tanren)

The term tanren, describes both the processes involved in preparing the raw tamahagane and making it ready for swordmaking. When tamahagane reaches Mr. Kawachi it is not ready to be made into a sword. Nor does the tamahagane resemble steel, as most readers would envision it. The raw material looks like a shiny and spongy rock. The processes involved in tanren are some of the most unique and important skills mastered only by traditional Japanese sword makers today (the other being quench-hardening). There are different ways to perform tanren; many considered trade secrets.

The steel is refined and strengthened while undergoing the forge-folding process.

There are several ways that a smith might begin to prepare the raw material. For example, in a process called mizū-beshi, the raw tamahagane is hammered out into thin wafers. The wafers are then quenched, making them very brittle. The smith crunches the brittle steel into smaller flat chunks about 4 cm wide. The fracturing allows them to be sorted into groups of varying carbon content and overall quality.

After the raw steel is hammered out and sorted, the smith undergoes a process of refining the steel by forge-folding—the actual tanren—a process similar to kneading dough. These pieces will eventually be expertly combined into a single chunk of steel that possesses carefully controlled qualities. This enables the smith to select steel for particular applications. For example, steel with higher carbon content is better suited for the jacket of a sword. Steel with lower carbon content would serve better within the core of a blade. Groupings all depend on the carbon content, crystalline structures, amount of impurities, and degree of consistency.

Each steel grouping will have a role to play in the finished product. Shingane, the soft core-steel (forge-folded only four to six times), serves the important function of keeping the sword from becoming too brittle. Steel with high carbon content will be very dense and rigid. This hard steel will become a jacket in which softer steel will nest. Called kawagane, the jacket steel will be folded between ten and fifteen times depending on the construction method used. In due course, these two types of steel will be welded together seamlessly.

Tanren, the process of folding and refining the sword steel described above, represents the most critical aspect of the swordsmith’s work, along with yaki-ire, the quench-hardening of a blade. It is a common misconception that swords are folded thousands of times. In reality, the jacket steel is folded ten to fifteen times. This results in multiple layers being doubled with each fold. The end result is a surface-steel displaying a grain, or jihada, that is the result of approximately 1,024–32,768 layers—not folds. In most blades, these layers can be seen by the naked eye when a blade has been well polished. The slight variances within the carbon-content of the jacket steel make the folds visible. The jihada layers appear as fascinating and intricate patterns.

The type of grain pattern, or hada, can be manipulated depending on the effect the swordsmith wants. Although grain is affected by many subtle factors such as the amount of carbon, the amount of impurities, and so on, the primary factor is the direction and number of folds the billet receives. Folding the steel, either lengthwise or perpendicularly, in relation to the final direction in which the sword will be lengthened, creates differing grain patterns. One of these, masame, resembles an elongated wood grain pattern, which runs the length of the sword. A common form of steel structure is itame, which looks like a swirling and knotty wood grain. Both itame and masame can be created in varying degrees and sizes. Others such as ayasugi (undulating grain) or mōkume (burly grain) can also be seen.

Mino sword smith Mr. Kanemichi uses a power hammer to work the steel with speed, efficiency and precision. Today, many smiths use a power hammer because young people are decreasingly interested in the traditional arts and trades.

These are two of the several methods of combining core and jacket steels.

Assembling a Sword’s Component Steels

The first steps of making a sword involve refining and preparing the raw materials in order to make them usable. Next, during the tsūkūri-kōmi process the billet is assembled combining carefully prepared steels—each with differing carbon content. There are several construction methods for combining the hard jacket steel with the tough core steel. Some use two pieces, some use up to five. Here, we shall limit ourselves to a brief explanation.

In the kōbūse construction method, the jacket steel is hammered into a “U” shape, which will contain the softer core steel inside.¹ The core steel is enclosed within the folded jacket steel in the same way that a hot-dog is placed inside its bun. The two are welded together to create the soft-core/harder-jacket combination (called kōbūse-gitae). That is one of the features that make Japanese swords so unique, distinguishing them from their celebrated Toledo or Damascus counterparts. Four and five-piece billet assemblies are another option. Such blades integrate steel of low, medium, and high hardness. Some believe that these more complex billet designs create a superior blade.²

The billet is elongated until it becomes a sūnōbe—a flat blank without a profile.

The blank has been hammered into a rough blade profile—a process called hi-zūkūri.

Visible here is the clay slurry that has been painted on the blade to insulate the steel during the heating and quench-hardening process. Clay application for three common temperline patterns are shown.

Elongating the Billet

Assisted by his apprentices, or for those working alone, using a power hammer, the smith hammers out the billet and it gradually becomes elongated. The smith pounds a cadence with his mallet and turns the billet underneath the apprentices’ hammers. A steady tempo of hammer strikes creates a rhythm that helps create a smooth collaboration between the smiths and his apprentices. If hammering were to accidentally push through the kawagane to the shingane, exposing the core steel, it would ruin the blade. So the hammers pound steadily and carefully, in a mesmerizing rhythm to create the sword blank, or sūnōbe, with precision and care. The geometry of the sūnōbe is tapered and rectangular. At this point the metal is long and more or less rectangular when viewed as a cross-section, as if it were cut from a sheet of steel. At this stage the sūnōbe appears to be one solid and seamless bar.

Creating the Profile

The process of hammering the sword blank into a profiled rough blade is called hi-zūkūri. The swordsmith works to shape the various surfaces of the blade a few inches at a time. Any mistake at this point would be difficult to correct. So as the sword progresses, there is less and less room for mistakes. When this stage is completed, the makings of what will become the distinctly Japanese sword shape emerge. When hi-zūkūri is completed the blade is still straight.

The shape and geometry of the blade are further refined using waterstones, files and drawknives made from hardened steel. Although the edge is still a blunt 2–3 mm thick, the filing and cutting away of inconsistencies leaves the sword looking quite exact in its geometry—a critical prerequisite for the next step. When all the lines are correct the smith is ready to proceed with creating both the curve and performing the heat treatment: he can proceed the yaki-ire process.

Quench-Hardening the Steel

When steel is heated above a certain temperature and then quickly cooled, its carbon atoms don’t have the time to travel out of the unstable molecular structure that higher temperatures allow, and are locked within, giving way to a highly stressed and hardened material. In the craft of sword making this phenomenon is used in the selective hardening of a sword edge. This process in sword making is called yaki-ire. The difference in hardness between the edge and the body of the blade allows the creation of the hardening mark, or hamon. The carbon content of the steel along with the rate at which the steel cools dictates the hardness that it will attain; the higher the carbon, and the faster it cools, the harder the steel. By allowing the steel at the edge of the sword to cool more quickly than the steel on the sides and back of the blade, a differential is created. The edge steel is extremely hard, whereas the jacket/sides remain only moderately rigid. Meanwhile the soft core prevents the blade from becoming brittle.

The creation of a hamon is a delicate and complex task that must be approached in an exacting manner. Due to its beauty and mysterious flowing appearance, the hamon is one of the most distinctive elements of nihōntō. Volumes have been written on the subtle effects that have been created by different smiths over the millennia. The names of such effects liken their beauty to awesome elements of nature, from the brilliance of stars in the night sky to the esoteric allure of rising lightning.

In one common way to create the hamon, Mr. Kawachi paints a clay slurry onto the blade, which acts as an insulator. The thickness of the clay dictates the rate at which the steel will cool and thus the extent to which it will harden. The clay is applied thickly at the back of the blade and thinly near the edge. The slurry is applied in such a way that the different thicknesses produce a pattern that will become the hamon. These patterns can be relatively straight (sūgūha), semicircular waves (gunome), elongated waves (nōtare), or made to look like clove buds (choōji), to name a few.

After quenching the blade, Mr. Kawachi removes the clay and examines the newly created hamon on the steel.

When the slurry has been applied, the blade is ready to be heated and quenched. Mr. Kawachi heats the blade very carefully. The color of the glowing steel indicates the temperature, so the quench-hardening is done after the smithy has been plunged into darkness. Different effects can be created depending on slight differences in temperature on different surfaces of the blade. One wrong move and the sword could come out of the process fatally damaged. So it is with a careful eye that the smith watches, awaiting the perfect opportunity to quench the blade by dunking it into a trough of water.

At the precise moment, Mr. Kawachi decisively thrusts the blade into water. With a quick hiss and bubble, the hardened edge is produced. The sword’s metamorphosis during this moment is astonishing. First, the edge steel cools, quickly bending the blade’s curvature against the edge—in the opposite direction that it should go. Then, as the back of the blade cools and contracts, the curvature actually reverses creating the edge-forward shape. As a result of this process, the blade, which was nearly straight, now has an elongated edge. The graceful and deadly curve of the distinctive nihōntō is born. Removing the clay slurry, the smith reveals a crude view of the steel. After this transformation the blade requires some final shaping.

Final Shaping

Mr. Kawachi removes the clay. Using files and low-grit stones, he exposes the steel underneath and begins shaping the sword. He continues his work, carefully adjusting the lines and overall geometry. As the steel’s surface becomes smoother, the hamon begins to appear—the first glimpse of the blade’s unique temperline. A hamon is similar to a fingerprint—no two are exactly alike. Once the sword-smith’s shaping is complete, he considers whether he wants to carve grooves, decorative bas-reliefs, or in this case a poem, into the blade.

If hi (grooves) or hōrimōnō (decorative carvings) are to be cut into the surface of the shinōgi-ji, the surface between the center ridgeline and the back edge, it is done at this stage, before sending it off to the polisher. According to Mr. Kawachi, “Hōrimōnō engravings were originally intended to serve as religious talismans.”³ On the other hand, grooves serve both practical and aesthetic functions. Here, we see Mr. Kawachi carving a distinctive inkan motif into one of his blades. Inkan are usually stone seals, stamped in red, which serve as someone’s signature. Grooves, on the other hand, are highly functional. Coming in several varieties, grooves lighten the blade, making it easier to wield, while simultaneously maintaining structural rigidity. Although this might seem counterintuitive at first, blades with grooves remain strong in the same way that an I-beam does.

The smith waits before signing the blade to see if the finished product will meet his personal expectations. Much of the sword’s finishing work is yet to be done. Only a basic view of the hamon can be seen at this point. In this rough condition, the smith delivers the blade to the polisher for further refinement.

The Polishing Process

A professional, certified mūkansa-level tōgishi like Mr. Abe is a craftsman of the highest order. The tōgishi’s time is incredibly valuable. The polisher must use his expertise to determine the proper course of action for any given blade. Polishing a newly made sword can take nearly two weeks. The waiting list for a mūkansa-level tōgishi like Mr. Abe can be years long.

The stones themselves also warrant appreciation. Stones used in polishing swords are extremely expensive. In ancient times, they were prized gifts offered among feudal lords. Top polishers like Mr. Abe spend untold fortunes on innumerable stones. Each stone will interact with steel differently. Each sword will require a slightly different stone to highlight its beauty. Therefore, most sword polishers have large collections of stones.

The process of polishing a nihōntō is extremely demanding in time, knowledge, and physical skill. Mr. Abe has allowed me to incorporate material from our interviews, his writing, and his collaboration with Paul Martin for the purpose of accurately illuminating the polishing process.

Polishing a sword can be broken down into two main processes. The first process, foundation polishing (shita-ji-tōgi), involves refining the shape of the sword by rubbing it over a series of stones. The second, finish polishing (shiage-tōgi) is performed by moving finger-stones over the blade’s surface. Each of these processes can be broken down into several sub-tasks, each of which requires a particular stone. The steps, stones, and intended outcomes are summarized below.

Carving hōrimōnō into a blade requires great skill and a steady hand.

An example of a polishing workstation.

Wafer-thin pieces of narutaki are ready to be sliced into tiny pieces and assembled on thumb-tip for fine polishing.

A small sampling of polishing stones.

Foundation polishing consists of three main goals: a. Shaping the blade, b. Refining the shape, and finally c. Preparing the surfaces for finish polishing. It is during this process that the sword’s edge becomes sharp. Foundation polishing uses stones of a rough grit and therefore, must be done carefully so as not to ruin the geometry of the sword. The goals of foundation polishing, while avoiding the removal of too much steel, are to make the surfaces of the blade even, keep the ridge-lines formed correctly, and maintain the sword’s visual balance. This process also sharpens the edge of the blade. See the photo sequence on page 40.

The stones used for shaping the blade are the kōngō-dō and binsui-dō. Binsui-dō is used more frequently. With each changing stone, the sword is worked in varying directions, slowly and with great care. Too much pressure, or removing too much material could result in damaging the blade badly. The shaping of the blade is complete when the surfaces have been polished and the lines of the blade are geometrically correct.

The stones used for refining the blade’s surfaces are called kaisei, chō-nagura, and kōma-nagura. In refining the surface, all marks made during previous stages must be removed completely. To assist this, Mr. Abe marks two spots on the surface of the blade using ground deer antler and uses them as visual markers to guide his polish-strokes. Working the blade in alternating directions, this process slowly reveals the first glimpses of the hamon. With the surfaces refined, the polisher can move to the next step, using the ūchigūmōri stones.

The purpose of the ūchigūmōri stones is to start bringing out the blade’s artistic qualities. From this stage on, the shape and sharpness of the blade remains unchanged. Using the ūchigūmōri stones serves to reveal the grain structures by further removing scratches left from previous stones. Two stones and sub-processes are used here; the hatō and jito.

The hatō stones are used mainly on the hamon with sparing application on the rest of the blade. Mr. Abe explains, “the brightness of the niōi-guchi, the length and visibility of the ashi and hataraki in the ha, all depend on the effectiveness of the hatō polishing stage.”

While the hatō stones improve the areas within the hamon, the jito stones are used to further refine the jigane, or grain-showing areas behind the hamon. Again, Mr. Abe clarifies this process saying, “As the jigane [grain properties] is different in all periods and schools, it is necessary for the polisher to bring out the characteristics associated with those schools.” The jito stage is the final process in which the blade is moved over the stone.

When the polisher completes his initial work with the blade it goes to the kōshirae/habaki maker, yet another highly skilled and specialized craftsman. The habaki must meet very exacting requirements. The habaki is not only functional, but aesthetically beautiful as well. It serves to wedge the sword safely in the scabbard by pressing outward on the inside surfaces of the opening, or the koigūchi’s habaki-būkūrō (habaki-bag). It also helps to keep the sword’s surfaces from scraping along the insides of the saya. If other fittings are required, they would likely be made and fitted by another craftsman. When the fittings are complete they would be delivered to the saya maker for inclusion and fitting onto the overall scheme of the furniture.

The saya maker is responsible for providing a resting place for the sword. The saya must be a good fit, not allowing the blade to rattle around inside. If the saya is made too tightly, however, the blade’s surface will be scuffed, ruining the polish. The scabbard is made of hōnōki wood, the Japanese equivalent of magnolia. The primary reason hōnōki wood is used is that it is soft enough that it won’t scratch the polish of the blade. Hōnōki is also preferred because it can be worked easily for a perfect fit and has low sap content.⁴ All of these traits make hōnōki the best choice for storing and preserving nihōntō.

Images 1–4 illustrate the process of foundation polishing (shita-ji-tōgi) in which the sword’s shape is refined by moving the blade over a series of abrasive stones.

When the wood is selected for saya making, the craftsman avoids irregular, knotty or gnarled pieces. The general outline of the saya and tsūka are cut out of the board as one long form. This creates a rectangular, but curved “blank,” from which the saya and tsūka will be cut. The blank is then cut down the middle lengthwise to create two halves. Each half is smoothed and prepared for chiseling. The bare sword blade is used to trace an outline on each half of the scabbard/tsūka blank. Using the outline of the sword, the saya maker carefully chisels ribbons of wood out of what will become the hollow of the scabbard. He repeats the process of hollowing out half-a-blade’s-width out of the other side.

When the two halves are hollowed out, the saya maker glues the halves together with a weak rice glue, which allows future splitting for maintenance. The same process is repeated for the tsūka, creating a custom, tight fit. When the tsūka is glued together the mekūgi-ana is drilled, and the mekūgi is positioned so as to hold the sword in the tsūka. The two halves, with the blade inserted, are then sealed together. With the pieces all assembled, the craftsman scribes lines down the length of the tsūka and saya. He uses these lines to carve and shape the outside of the tsūka and saya. In the case of a storage shirasaya, the finished shape can be octagonal or oval.

If kōshirae are requested, the saya maker is one of the many craftsmen who could accommodate them into his design and fit them onto the finished product. The saya may require lacquering and possibly other decorative additions.

All of the sword’s fittings must be carefully chosen for the finished product. Generally speaking the kōshirae follow an elegant theme and are designed to be used as a set. Swords whose fittings have been retrofitted and consequently have the design themes interrupted are considered to be less appealing.⁵ Everything from the application of same (belly skin of a ray) to the wrapping of the hilt, or tsūka, is considered to be essential to the completion of this piece of art. Whether the blade will receive a shirasaya or full fittings, once it has been furnished, it will be returned to the polisher for the final polishing stages.

Shiage-tōgi: From here on, the polisher will hold the blade and carefully move small finger-stones and tools over its surfaces. Here, the fine-art qualities emerge slowly. These processes require careful selection and application of stones for a given blade. Any mistakes at this stage would likely require the polisher to go back several steps to reset the surface. Shiage-tōgi subtasks include:

a. Working with the jizūya stones, b. Applying nūgūi solution, c. Hadōri, d. Migaki (burnishing), and e. Finishing the tip with sūjikiri and narūme.

The jizūya process is known for its application of finger-stones. Here, Mr. Abe takes wafer-thin pieces of narutaki and cuts them into miniscule pieces. See photo 5 below. Carefully transferring them onto his thumb, Mr. Abe rubs the hiraji methodically. He explains, “The brightness of the jigane, and the fineness of the hada is obtained by the quality, hardness and thickness of the age-jizūya used. To bring out the subtle characteristics of a fine hada is of great importance to the finished polish. The polisher has to know when to stop bringing out the hada or it will become too prominent.” He indicates that it takes a great deal of knowledge and experience to know what stone to use and how long to use it to bring produce a fine hada.

Images 5–8 illustrate the process of finish polishing (shiage-tōgi) in which the sword’s surface is smoothed by painstakingly moving finger stones over the blade.

The next step in the polisher’s task is to apply an iron-oxide and clove oil solution called nūgūi. This mixture is dabbed along the length of the blade and then rubbed into the steel using a cotton ball. See photo 8 on the previous page. The purpose of this is to homogenize the color of the jigane and give the correct tone to the steel. The school, era, and type of the sword are all factors that must be considered when determining how much nūgūi to apply. Nūgūi will not brighten the blade so it takes experience to know what is the right amount.

The waves of the hamon are the accentuated by the polisher. Here the polisher must decide how he will enhance the overall flow of the real hamon. Whitening the area of the hamon is called hadōri.

This process also highlights the crystalline structures, called niōi and nie, making them bright and clearly discernable. Mr. Abe explains, “Every hamon follows a rhythm or melody line that is indicative of the smith that constructed it.”

Images 9–14 illustrate the final, critical steps in polishing the blade. Here the temperline pattern is artfully accentuated, the finish is burnished to a high luster, and the tip is delineated.

Before actually performing hadōri, Mr. Abe does something rare in the world of sword polishing. He uses a mixture of powdered deer antler to paint the hadōri-line onto the blade. See photo 9 on page 42.This is a special technique he learned as part of the Ono School of sword polishing, a trademark of Ono Kokei, the Living National Treasure sword polisher. In essence, this step allows the polisher to foresee what the hadōri will look like when completed and make any last minute changes to his stone selection, line creation, and so on. The goal of creating the hadōri is to create a gracefully flowing line that highlights the work of the smith while maintaining visual balance.