Japanese Katana Construction

The legitimate Japanese sword is made from Japanese steel "Tamahagane". The forging of a Japanese blade typically took hours or days, and was considered a sacred art. As with many complex endeavors, rather than a single craftsman, several artists were involved. There was a smith to forge the rough shape, often a second smith (apprentice) to fold the metal, a specialist polisher, and even a specialist for the edge itself. Often, there were sheath, hilt, and tsuba specialists as well.

The steel for the swords is produced by smelting iron sand in a large clay furnace called a tatara. The steel bloom, or kera, produced contains steel that varies greatly in carbon content, ranging from wrought iron to pig iron. Three types of steel are chosen for the blade; a very low carbon steel called hocho-tetsu is used for the core of the blade, called the shingane. The high carbon steel, called tamahagane, and the pig iron, called nabe-gane, are combined to form the outer skin of the blade, called kawagane.Only about 1/3 of the kera produces steel that is suitable for katana production.

The most famous part of the manufacturing process was the folding of the steel. Japanese swords and other edged weapons are manufactured by the Chinese method of repeatedly heating, folding and hammering the metal. The low carbon hocho-tetsu is folded several times by itself, to purify it. The high carbon tamahagane and the higher carbon nabe-gane are then forged in alternating layers. The nabe-gane is heated then quenched in water, and then broken into small pieces to help free it from slag. The tamahagane is then forged into a single plate, and the pieces of nabe-gane are piled on top, and the whole thing is forge welded into a single block, which is called the age-kitae process. The block is then elongated, cut, folded, and forge welded again. This process, called the shita-kitae, is then repeated from 8 to as many as 16 times. After 20 foldings, (220, or about a million individual layers), there is too much diffusion in the carbon content, and the act of folding no longer gives any benefit to the steel. This process forms the kawagane, (or, skin-steel). Careful positioning of the grain in the steel is used between layers, differing, depending on what part of the blade the steel will be used. The steel is coated in a mixture of clay, water and straw-ash to protect it from oxidation and carburization. The clay, in turn, acts as a flux, pulling impurities out from between the layers.This practice became popular due to the use of highly impure metals, stemming from the low temperature yielded in the smelting at that time and place. The folding did several things:

• It provided alternating layers of differing hardenability. During quenching, the high carbon layers achieve greater hardness than the medium carbon layers. The hardness of the high carbon steels combine with the ductility of the low carbon steels to form the property of toughness.


• It eliminated any bubbles in the metal.


• It homogenized the metal, spreading the elements (such as carbon) evenly throughout - increasing the effective strength by decreasing the number of potential weak points.


• It burned off many impurities, helping to overcome the poor quality of the raw Japanese steel.


• It created up to 65000 layers, by continuously decarburizing the surface and bringing it into the blade's interior, which gives the swords their grain (for comparison see pattern welding).

Generally, swords were created with the grain of the blade (called hada) running down the blade like the grain on a plank of wood. Straight grains were called masame-hada, wood-like grain itame, wood-burl grain mokume, and concentric wavy grain (an uncommon feature seen almost exclusively in the Gassan school) ayasugi-hada. The difference between the first three grains is that of cutting a tree along the grain, at an angle, and perpendicular to its direction of growth (mokume-gane) respectively, the angle causing the "stretched" pattern. The blades that were considered the most robust, reliable, and of highest quality were those made in the Mino tradition, especially those of Magoroku Kanemoto. Bizen tradition, which specialized in mokume, and some schools of Yamato tradition were also considered strong warrior's weapons.

One of the core philosophies of the Japanese sword is that it has a single edge. This means that the rear of the sword can be used to reinforce the edge, and the Japanese took full advantage of this. When finished, the steel is not quenched or tempered in the conventional European fashion. Steel’s exact flex and strength vary dramatically with heat variation. If steel cools quickly, from a hot temperature, it becomes martensite, which is very hard but brittle. Slower, from a lower temperature, and it becomes pearlite, which bends easily and does not hold an edge. To control the cooling, the sword is heated and painted with layers of sticky clay. A thin layer on the edge of the sword ensures quick cooling for a hard edge, with a thicker layer of mud on the rest of the blade causing slower cooling and softer, more bendable steel to allow the blade to bend instead of breaking. When the application is finished, the sword is quenched and hardens correctly. This process also makes the edge of the blade contract less than the back when cooling down, something that aids the smith in establishing the curvature of the blade.

Eventually the Japanese began to experiment with using different types of steel in different parts of the sword.

The vast majority of good katana and wakizashi are of wariba-gitae type. The makuri-gitae is made using two steels, one folded more times than the other, or of a lesser carbon content. When both sections have been folded adequately, they are bent into a 'U' shape and the softer piece is inserted into the harder piece, at which point they are hammered out into a long blade shape. By the end of the process, the two pieces of steel are fused together, but retain their differences in hardness.

More complex models allow for parrying without fear of damaging the side of the blade. To make han-sanmai-awase-gitae or shiho-zume-gitae, pieces of hard steel are then added to the outside of the blade in a similar fashion. The last generally accepted model, the shiho-zume-gitae, is quite rare, but added a rear support.

the way of sharpen the knives blade ?

SHARPENING PROCESS

COMMON MISTAKES
The mistakes commonly made in knife sharpening are uncontrolled edge angles, failure to establish a new edge, and leaving the edge too rough. The following methods address each of these mistakes.
The keys to success are:
1) Use an angle guide to control the edge angle,
2) Sharpen until you raise a burr, and
3) Hone or polish the edge smooth.
Some instructions refer to the sharpening motion as trying to slice a thin layer or a decal off the stone. This is bad advice, and here's why: most people won't hold a constant angle this way. Every different edge requires that you hold the blade at a different angle when slicing a thin layer. You instinctively raise the blade until you detect the edge working. This is almost a sixth sense, involving both feeling and hearing. The same thing happens when sharpening by hand. The duller the blade becomes the more you raise it more before you can sense the edge working against the stone. This creates larger edge angles as time goes on and the results gradually deteriorate. Skill and practice will overcome this problem, but the sure-fire way is to use a guide to maintain edge angle.
If you do not remove enough metal to create a new edge, you will leave some of the dull edge in place. The easiest way to determine that you have removed enough metal is to grind until you have raised a burr. Steel will naturally form a burr when one bevel is ground until it meets another. You can then remove the burr in the honing process and have a sharp edge every time.
A final honing and polishing will bring the edge to perfection.

CONVENTIONAL METHOD
For fast removal of the old edge, start with a coarse, fast cutting stone. Diamond stones are the fastest cutting manual stones, with Japanese waterstones second. The first step is where most of the work is, and you can benefit most from using a power sharpener.
Set the guide and take a light stroke with the stone. Check the angle against the old bevel. If the new scratch pattern is on the back edge of the old bevel, you are lowering the angle. If it is at the edge, the angle is being increased. When the scratch pattern is centered on the bevel you are duplicating the original angle. Keeping the original angle is a safe strategy until you gain more knowledge.

If you can't see the scratch pattern, try darkening the old bevel with a black felt tip marker, then stroke the stone again. The scratch pattern will stand out against the dark marking.
When the angle is set correctly, grind one side of the blade until you have removed the old edge. Grind until you have raised a burr. The burr will appear on the side opposite the one you are grinding. With experience you will learn how to stop with just a small burr in this step. If you are not sure, grind until you can feel the burr. Then turn the blade over and grind an equal amount off the second side.
A burr is a natural occurrence in steel when one bevel is ground until it meets another. When I was learning I would show my work to my grandfather, and he would often show me that I had a burr. It seemed sharp, but the burr would bend over and become dull. I tried to avoid ever raising a burr for years after that. As a result I never got anything quite sharp. Now I know that one of the secrets of sharpening is to raise a burr, then hone it away.
Ceramic knives and some very hard steel will not raise a burr. Here again experience will tell you when you have ground enough.
There are three basic strokes when you sharpen - sliding the stone onto the edge, sliding it off the edge, or circular or alternating strokes. At the first stage, any of the three is okay.
For the next step use a medium stone. Its purpose is not so much to remove material as to grind away the scratches made by the first stone. The medium stone should be about twice as fine as the first. If you started with a 180 grit stone, you can use 320 or 360 now. Use circular or alternating strokes until the old scratch pattern is gone. Then do an equal amount of grinding on the second side.
You might still be able to detect a small burr at this stage. Finish with a few light strokes sliding onto the edge to remove the burr. This is where slicing a decal off the stone is an accurate description. The blade should now be sharp with no burr. The edge now has 320 or 360 grit micro-serrations, which is good enough for many uses.
The micro-serrations are providing some of the apparent sharpness now but they will wear and bend. A steel or a touch-up stone will straighten them and bring back the sharpness. Continue to the next step if you want a longer lasting edge.
For the third step use a fine stone, 600 or 800 grit, and hone using only strokes going onto the edge. Alternate sides with every stroke. This will help prevent forming a new burr.
Your edge should now shave. Test it as described above. If there is roughness, go back to the medium stone. If there is no roughness but the edge doesn't have enough bite, continue with the fine stone.
When the blade becomes dull, repeat the medium and fine stones. Only when the blade becomes nicked or damaged will you need to go back to the coarse stone.

MULTI-BEVEL METHOD

This variation will give you a longer lasting edge than the conventional method described above. The multi-bevel edge that results is similar to the convex edge found on Moran and BlackJack knives and the Trizor edge on Chef's Choice knives. This method can be adapted to many types of sharpening equipment.
The first step is to grind an initial edge bevel about 5 degrees less than you want your final angle. This is sometimes referred to as pre-sharpening or thinning the blade. You will put a little more work into this step, but you will save some work later. Grind until the old edge is removed. As described above, the proof is that you have raised a burr.
Now change to a medium stone and set your guide for a few degrees greater angle. On a clamp-on type guide you increase the angle by moving the guide closer to the edge. On a rod type systems you can easily select another angle. Other systems have different ways to adjust the angle. See the section below for a method using the Lansky sharpener.
When you get to the fine stone increase the angle again another couple of degrees. Hone with strokes going onto the edge and alternate sides with every stroke. You are now grinding only a small area right at the edge, removing the burr and the scratches from the medium stone.
Since a finer stone cuts more slowly, it usually takes quite a bit of work to remove the previous step's scratches. By increasing the angle by a couple of degrees when you change stones, you focus this work on a smaller area near the edge and reduce the work needed

MULTI-BEVEL WITH A LANSKY SHARPENER
Here is an easy way to do a multi-bevel with the Lansky:
1. Push the rod into the coarse stone as far as it will go and still have the screw tighten against the flat. This decreases the angle by a degree or so. Do extra-coarse stones the same if used.
2. Mount the rod on the medium stones in the center of the flat per the instructions.
3. Push the rod into the fine stone only far enough to tighten the screw against the flat. This increases the angle by a degree or so. Do the ultra-fine the same if you have one.
Now, when using these stones you will automatically create a three bevel edge.
Tip: Replacing the thumb screws with flat head screws will give you another 1/2 inch or so of useful stone.

HONING
You can further improve the edge by honing the edge on an ultra fine Japanese, Arkansas or ceramic stone, 1000 grit or better. Maintain the same angle as the final step above.

USING OILS AND WATER ON STONES
In North America we usually use oil on sharpening stones; in the rest of the world they use water. Tests by John Juranitch show that because oil carries the dross against the edge, better results are obtained with a dry stone. However, natural stones tend to clog without oil. I prefer ceramic and diamond stones used dry, and my second choice is Japanese waterstones.
I'll leave this up to your personal preference, with the following guidance. With India and bonded Arkansas stones you can use oil or use them dry. Clean them with paint thinner. Use and clean Japanese waterstones only with water, but store them dry and soak them before using. Ceramic and diamond stones can be used dry or with water. Clean them with water and scouring powder when necessary. Washita and natural Arkansas stones can be used with oil, water or dry, and cleaned accordingly.
If you have used water on a stone and want to change to oil, let it dry thoroughly, and then oil it. Once you have used oil on a stone, it is difficult to change back.

Hope it is helpful for you

Japanese Sword Development

During the Mongolian invasion of Japan (Kamakura period), a great samurai warrior from the Minamoto clan residing in Sagami (the Soshu Province) commissioned a local master swordsmith to create a daito, or long sword. Soon after, he encountered a group of nine armed warriors. With skill and grace, he defeated the group by himself. Before the next battles of the day, he chose to clean his swords. He found a secluded spot, hidden from view in the woods. He pulled from his obi a small black cloth pouch, which held his uchiko (limestone powder), cleaning cloth, and oil of clove. While cleaning and inspecting his newly acquired daito, he noticed the blade was unscathed. His past blades hadn't had nearly the same strength, flexibility or sharpness as this new blade. His strong, sharp sword and expert technique helped him to gain a reputation of fierce excellence. With this sword, the samurai warrior helped his clan along with all of the other samurai clans from Kamakura defeat the Mongols, reinforce the strength of the feudal government and unify the spirit of Japan.
The Japanese samurai sword's development paralleled the history of Japan. Soon after the first empire of Japan was established (roughly at the start of the Christian era), the art of weapon making was brought from China and Korea. The Chinese and Korean swordsmiths taught the Japanese how to make swords, but it was the Japanese who perfected the art of swordmaking throughout centuries. This was largely due to the way the Japanese people were about life-meticulous and idiosyncratic. The swordsmith was clean and reverent, with the greatest respect for every detail. His rituals would include praying, wearing white, and performing misogi purification. The process required complete focus and concentration.
The ancient sword period-also known as the ken or the straight sword period-lasted about 300 years. The swords of this era were made of steel; however, the hardening process was not perfected. The quality of the edge and strength of the sword was affected by the lack of understanding of the hardening process. Some blades were double edged and some were single edged, and they all imitated the Chinese blade styles.
Through the Nara and Heian periods in Japanese culture, swordmaking remained in the ancient period, making little headway. The need for a better quality sword arose.
A legend states that a swordsmith, Amakuni Yasutsuna, was the leader of a group of swordsmiths. They made swords for the emperor and his warriors. One time, Amakuni and his son Amakura watched the emperor and his warriors returning from battle. They noticed most of the swords brought back were broken or badly damaged. They gathered some of the broken swords to examine, realizing that the reason for the failure was due to incorrect forging. So for one week Amakuni and Amakura prayed to the Shinto gods and purified themselves by misogi meditation. Then they gathered the finest ore and refined it to create the first single-edged sword with a curved blade. It was polished and presented to the emperor. The other swordsmiths thought this was insane; however, as the days went on Amakuni and Amakura continued their efforts to improve technique and created many swords in this fashion. The next time the warriors returned from battle, virtually all of the blades they brought back were intact and in excellent condition. (This legend was passed down from the swordsmiths of the Yamato province.)
In the middle of the Heian period of Japanese culture, the next sword period-called koto or old sword period-took place. The need to stay connected to China diminished and the art of Japanese samurai swordmaking leaped ahead. The swords that emerged from the latter part of this era are of the finest made to date and are the most sought after by collectors and the Japanese government of today as examples of national treasures.

The Japanese Sword History

For a direct link to the official NBTHK chart of the changes in the shape of the Japanese sword please click here.
Jõkotõ (Chokutõ) Ancient and Heian period Late Heian to Early Kamakura Mid-Kamakura Late Kamakura Nanbokucho Early Muromachi Late Muromachi Aizuchi-Momoyama Mid-Edo Edo period Genroku era Edo, Bakamatsu Meiji and onwards
1. Jõkotõ
Jõkotõ are straight blades with no curvature. They are usually constructed in the hira-zukuri and kiriha-zukuri styles. It is thought that the shift from straight blades to Japanese swords with curvature happened around the mid to late Heian period (794-1184). This was during the mid 10th century: about the time Taira Masakado and Fujiwara Sumitomo rebelled against the government in the Johei (931-938) and Tengyo (938-947) eras. Blades before these are continental style blades called jõkutõ, and were brought to Japan from the Asian continent. Examples of these blades have been excavated from Kofun period tombs, and some still reside in the Shosoin Imperial Repository, Nara.
2. Late Heian to Early Kamakura
From the late Heian period and the early Kamakura period (1185-1333) we can see the Japanese sword as we know it: shinogi-zukuri (ridgeline) construction, with a wide base, narrowing acutely towards the small point section (ko-kissaki). They are quite slender blades with the curvature concentrated between the handle and base. This shape is called koshi-zori. From midway towards the point there is very little curvature. These blades are usually around 2.5-6 shaku in length (75.8 cm-78.8 cm)
3. Mid-Kamakura
At the zenith of the warrior class’s power during the Kamakura period, the blade’s kasane becomes thick, the mihaba becomes wide and they take on magnificent tachi shape. There is not much difference between the size of the moto-haba and the saki-haba. The blade still has koshi-zori, but the center of the curvature has moved further along the blade. The kissaki has become a compact chu-kissaki (ikubi). The hamon has developed into a flowing gorgeous choji-midare. Also around this time, tanto production appears.
4. Late Kamakura
Tachi at the end of the Kamakura period have developed into magnificent blades. There are two types: one is wide throughout its length and the point section is the same as mid- Kamakura period kissaki, but slightly extended. The other is quite slender and similar in appearance to the late Heian, early Kamakura shapes. However, when you look further along the blade the shape has changed; the curvature has moved further along the blade. During this period notare-gunome hamon appeared. It is said that in Sagami province Goro Nyudo Masamune perfected the production of nie-deki blades.
5. Nanbokucho
During the Nanbokucho period many long blades of three shaku (90.9cm) and other long tachi were made. Tanto of large proportions were also produced. Tachi were majestic, wide, and proportionally long. Among these were some over 90 cm in length and worn over the back. These types of blade are called no-dachi and o-dachi. They were rather thin in construction to decrease the weight. Additionally, many have a bo-hi (groove) cut into the shinogi-ji area in order to lighten the blade. Many tachi from this period are o-suriage (shortened in later periods as they were difficult to wield). Consequently, many extant blades from the Nanbokucho period are unsigned.
6. Early Muromachi
Blades of the early part of the Muromachi period are reminiscent in construction to the blades of the early Kamakura period. When compared to the shape of the Nanbokucho period, the shape has completely changed and no longer includes o-kissaki. At around 2.4-5 shaku (72.7 cm-75.7 cm) in length, they are quite narrow and deeply curved with a medium-sized point section. At first glance they may appear somewhat similar to Kamakura period blades, but on closer inspection they are saki-zori character.
7. Late Muromachi
By the late Muromachi period, samurai fighting methods had changed from cavalry to mass infantry style warfare. Uchigatana, worn with the cutting edge uppermost thrust through the sash, had become popular. After the Onin war, conflicts broke out in many places and kazu-uchi mono began to appear (mass-produced blades inferior in quality to regular Japanese blades). However, specially ordered blades of excellent quality (chumon-uchi) were also produced at this time. Bizen (Okayama prefecture) and Mino (Gifu prefecture) were the major places of production. Many blades produced in this period are around 2.1 shaku (63.6 cm) in length. They are slightly wider than the standard width, with either a chu-kissaki or an extended chu-kissaki and strong saki-zori. The nakago are short, intended for one-handed use.
8. Aizuchi-Momoyama
Swords produced up to the Keicho era (1596-1614) are classified as kotõ (old blades) Blades made during and after this era are classified as shintõ (new-swords). When Japan entered the Aizuchi-Momoyama period, many smiths moved to Edo or Kyoto, or gathered in castle towns of various influential daimyo. Additionally, developments in transportation brought about experimentation with materials, and foreign-made steel (known as nanbantetsu) was utilized. The blade’s shape from around this period mirrors that of shortened Nanbokucho blades. They are generally wide with little or no difference between the moto and saki-haba. Many have an extended chu-kissaki, whilst some have o-kissaki, with a thick kasane and are usually around 2.4-5 shaku (72.7 cm-75.8 cm) in length.
For a direct link to the official NBTHK chart of the changes in the shape of the Japanese sword please click here.



Jõkotõ (Chokutõ) Ancient and Heian period Late Heian to Early Kamakura Mid-Kamakura Late Kamakura Nanbokucho Early Muromachi Late Muromachi Aizuchi-Momoyama Mid-Edo Edo period Genroku era Edo, Bakamatsu Meiji and onwards


1. Jõkotõ
Jõkotõ are straight blades with no curvature. They are usually constructed in the hira-zukuri and kiriha-zukuri styles. It is thought that the shift from straight blades to Japanese swords with curvature happened around the mid to late Heian period (794-1184). This was during the mid 10th century: about the time Taira Masakado and Fujiwara Sumitomo rebelled against the government in the Johei (931-938) and Tengyo (938-947) eras. Blades before these are continental style blades called jõkutõ, and were brought to Japan from the Asian continent. Examples of these blades have been excavated from Kofun period tombs, and some still reside in the Shosoin Imperial Repository, Nara.
2. Late Heian to Early Kamakura
From the late Heian period and the early Kamakura period (1185-1333) we can see the Japanese sword as we know it: shinogi-zukuri (ridgeline) construction, with a wide base, narrowing acutely towards the small point section (ko-kissaki). They are quite slender blades with the curvature concentrated between the handle and base. This shape is called koshi-zori. From midway towards the point there is very little curvature. These blades are usually around 2.5-6 shaku in length (75.8 cm-78.8 cm)
3. Mid-Kamakura
At the zenith of the warrior class’s power during the Kamakura period, the blade’s kasane becomes thick, the mihaba becomes wide and they take on magnificent tachi shape. There is not much difference between the size of the moto-haba and the saki-haba. The blade still has koshi-zori, but the center of the curvature has moved further along the blade. The kissaki has become a compact chu-kissaki (ikubi). The hamon has developed into a flowing gorgeous choji-midare. Also around this time, tanto production appears.
4. Late Kamakura
Tachi at the end of the Kamakura period have developed into magnificent blades. There are two types: one is wide throughout its length and the point section is the same as mid- Kamakura period kissaki, but slightly extended. The other is quite slender and similar in appearance to the late Heian, early Kamakura shapes. However, when you look further along the blade the shape has changed; the curvature has moved further along the blade. During this period notare-gunome hamon appeared. It is said that in Sagami province Goro Nyudo Masamune perfected the production of nie-deki blades.
5. Nanbokucho
During the Nanbokucho period many long blades of three shaku (90.9cm) and other long tachi were made. Tanto of large proportions were also produced. Tachi were majestic, wide, and proportionally long. Among these were some over 90 cm in length and worn over the back. These types of blade are called no-dachi and o-dachi. They were rather thin in construction to decrease the weight. Additionally, many have a bo-hi (groove) cut into the shinogi-ji area in order to lighten the blade. Many tachi from this period are o-suriage (shortened in later periods as they were difficult to wield). Consequently, many extant blades from the Nanbokucho period are unsigned.
6. Early Muromachi
Blades of the early part of the Muromachi period are reminiscent in construction to the blades of the early Kamakura period. When compared to the shape of the Nanbokucho period, the shape has completely changed and no longer includes o-kissaki. At around 2.4-5 shaku (72.7 cm-75.7 cm) in length, they are quite narrow and deeply curved with a medium-sized point section. At first glance they may appear somewhat similar to Kamakura period blades, but on closer inspection they are saki-zori character.
7. Late Muromachi
By the late Muromachi period, samurai fighting methods had changed from cavalry to mass infantry style warfare. Uchigatana, worn with the cutting edge uppermost thrust through the sash, had become popular. After the Onin war, conflicts broke out in many places and kazu-uchi mono began to appear (mass-produced blades inferior in quality to regular Japanese blades). However, specially ordered blades of excellent quality (chumon-uchi) were also produced at this time. Bizen (Okayama prefecture) and Mino (Gifu prefecture) were the major places of production. Many blades produced in this period are around 2.1 shaku (63.6 cm) in length. They are slightly wider than the standard width, with either a chu-kissaki or an extended chu-kissaki and strong saki-zori. The nakago are short, intended for one-handed use.
8. Aizuchi-Momoyama
Swords produced up to the Keicho era (1596-1614) are classified as kotõ (old blades) Blades made during and after this era are classified as shintõ (new-swords). When Japan entered the Aizuchi-Momoyama period, many smiths moved to Edo or Kyoto, or gathered in castle towns of various influential daimyo. Additionally, developments in transportation brought about experimentation with materials, and foreign-made steel (known as nanbantetsu) was utilized. The blade’s shape from around this period mirrors that of shortened Nanbokucho blades. They are generally wide with little or no difference between the moto and saki-haba. Many have an extended chu-kissaki, whilst some have o-kissaki, with a thick kasane and are usually around 2.4-5 shaku (72.7 cm-75.8 cm) in length.
9. Mid-Edo
Swords of the mid-Edo period are of standard width. The saki-haba is relatively narrow when compared to the moto-haba. The curvature is noticeably shallow with a small to medium-sized point section. They are usually around 2.3 shaku (69.7 cm) in length. This particular type of construction was generally produced around the middle of the Kanbun (1661-1673) and Enpo (1673-1681) eras, and is usually referred to as Kanbun shintõ.
10. Edo Period Genroku era
The change in shape of Japanese swords between the Jokyo (1684-1688) and Genroku (1688-1704) eras reflects the transition of shape from Kanbun-shintõ blades to the beginning of the shin-shintõ period of sword manufacture. As it was a very peaceful period in Japanese history, rather flamboyant hamon appear, and as opposed to that of Kanbun-shintõ blades, the curvature is quite deep.
11. Edo period Bakamatsu era
Blades made after the Bunka (1804-1818) and Bunsei (1818-1830) eras are referred to as fukko-shintõ (revival swords). Pioneers of the revival movement include Suishinshi Masahide and Nankai Taro Tomotaka. Taikei Naotane was among Masahide’s students. Minamoto Kiyomaro led a revival aimed at soshu-den and Mino-Shizu workmanship. Bakumatsu blades are shallow in curvature, have a wide haba with not much difference in width between the saki and moto-haba, and are around 2.5-6 shaku (75.7cm-78.7 cm) in length, with an o-kissaki and thick kasane.
12. Meiji Onwards (no image)
Blades made from the 9th year of Meiji until present day are referred to as gendaitõ (modern swords). As of the Hatorei decree in 1876 (banning civilians from wearing swords), the need for swords declined. However, in Meiji 39 (1906) the craft gained imperial patronage. The swordsmiths Gassan Sadakazu and Miyamoto Kanenori were appointed Tei Shitsu Gi Gei In (craftsmen by imperial appointment—equivalent to National Living Treasure). Since then, the swordsmith’s craft has continued through the Meiji (1868-1912), Taisho (1912-1926), Showa (1926-1989) and Heisei (1989-) eras until today. Today’s swordsmiths try to recreate the workmanship of eminent smiths of every period, regardless of whether they are kotõ, shintõ or shin-shintõ. In particular, recreations of tachi of the Kamakura period are a popular aim for many modern swordsmiths.

Special Japanese Sword Polishing Kit

This Japanese sword Polishing Kit almost all of the necessary items to polish Japanese Sword are set in this kit, such as several polishing stones and items for finishing work. these are the same quality as the professionals use. So having this kit, you are able to enjoy polishing sword at home as if you are a specialist, It is more reasonable to buy this kit than to buy each item separately, so get this kit and be fully satisfied with your own beautiful csword.
Contents of a set :U chigumori-do or Suita-do, Koma-nagura-do, Chu-nagura-doKaisei-do, Binsui-do, Kongo-doNarume-dai, Yoshino-gami, Kanahada-Nugui, Tsunoko, Ibota, Migaki-boHa-zuya"lacquered", Ji-zuya, Omotesuri"Nagura, Binsui, Omura"
How to use:The right order to use polishing stones and finishing tools.
1: 1) First, choose polishing stones according to your sword to grind and plish.
#1, Kongo-do >> #2, Kaisei-do>>#3, Kaisei-do>> #4 Chunagura-do>>#5, Komanagura-do>>#6, U chigumori-do
2: Split Hazuya into a small piece (the tip of the little finger size), and make it thinner by grinding it with #3, Kaise-do and #6, Uchigumori-do.After grinding your sword by #6, U chigumori-do, polish the part of Ha with Hazuya by the finger (thumb) cushion.
3: Split Jizuya into a small piece (the tip of the little finger size), and make it thinner by grinding it with #3, Kaisei-do and #6, U chigumori-do.After grinding your sword by #6, U chigumori-do, polish the part of Ji with Jizuya by the finger(thumb) cushion.
4: Wrap Kanahada up in Yoshinogami paper, then lacquer the filtered liquid from paper to the blade of your sword and polish it with cotton wool etc.Kanahada should be stirred up fully before using.
5: To get Tojiru(Liquid), Make an oval Hazuya, the same size as 2) and 3), and grind it with #6, U chigumori-do.Then to make Ha shining and white and to make your Hamon clear, grind the part of Ha with Tojiru by the tip on the thumb.This process is called Hadori.
6: Migaki-bo. This is used to polish Shinogi and Mune.First knead a small quantity of Tsunoko with Water, rub it on Shinogi and Mune to remove stains and wipe up the stains.Then polish it with Migaki-bo after making a smooth slide by tapping with Ibota wrapped in a piece of close.
7: Place a piece of paper on Narume-dai on which put down a thinly finished rectangular Hazuya to grind Narume (Kissaki).
Omotesuri-to make the surface smooth by small piece of stone-
Combination of polishing stone to make a face to face grinding.
Nagura>> U chigumori-doBinsui>> Komanagura-do and Chunagura-doOmura>> Kaisei-do and Binsui-do

MAJOR PARTS OF TSUBA

Tsuba (sword guards) are used to protect the hand from sliding onto the blade of a Japanese sword. They are art works in their own right and are widely collected. Some koshirae (sword mounts), mostly tanto, were made without tsuba (aikuchi koshirae). Tsuba were mostly made by specialized kodogu and tosogu (sword fittings) artists, although some sword makers produced tsuba (tosho tsuba) as did armour makers (katchushi tsuba). Some tsuba artists also made fuchi-kashira and menuki. In some cases the maker used a forged, folded plate; in other cases a homogeneous plate was used. Many tsuba are signed by the maker on the seppa-dai (area around the nakago ana). When mounted, the tsuba seppa-dai is covered by seppa (metal spacers) and the signature (mei) is not visible. Occasionally tsuba will be found with two small holes near the base of the tsuba. These are udenuki-ana which represent the sun and moon and were likely used for threading a leather wrist thong to prevent dropping the sword in battle.

Tsuba are commonly divided into two types; iron (tetsu) and soft metal (kinko). The kinko tsuba may be made of a variety of alloys; most commonly either shaduko (blue-black colored copper-gold alloy), sentoku (brown colored copper-lead-zinc alloy), shibuichi (gray colored copper-silver alloy), brass or copper. Both iron and kinko tsuba may have various carved and/or applied decor and/or cut-out designs (sukashi). Tsuba with extensive cut-out designs are commonly referred to as "sukashi tsuba". Depending on the style, the sukashi may depict designs in either positive or negative silhouette. See more examples of various styles of tsuba.

The most common shapes of tsuba are round (maru gata), rounded-square (kaku gata) and four lobed (mokko) with many variations within each basic design. The patina (surface coloration) gives the tsuba its beauty. Never clean tsuba or any sword fitting with metal polish, it will remove the patina and destroy the beauty and value of the item. Be aware that there are many modern replica and reproduction tsuba of varying quality on the market. These are excellent for mounting on martial arts swords, but are not considered collectible.

Damascus knives

Definition: the use of Uz ingot manufacturing, the surface has a pattern of casting-type knives, one edge of the world's three major Detailed Description: To see the beautiful drawings in a special pattern that it? That is the unique pattern of Damascus steel Pattern Damascus steel is the name of Europeans, The same as Arabic numerals, their origin is India. In the Middle Ages, India produced a Uz ingot is to produce top steel swords, The annual Arab businessmen to India must import large quantities of steel ingot for weapons manufacture. Such steel in the casting surface into a sword when there will be a special kind of pattern --- Mohammed pattern, Therefore, it is a pattern in steel casting-type pattern steel, formed from folded forged steel welding type pattern. Because the pattern can form a knife edge at the micro serrated (the naked eye can not distinguish), makes more sharp swords. Damascus steel on the magic of the pattern is artificially cut and polish the natural beauty. By moving its own legends and outstanding performance, made from Damascus steel knives, to become the best tool collections sector. In recent years some companies have used tin plating process to imitate the pattern of Damascus steel True Damascus steel, also known as the crystallization pattern of steel. Is an ancient technique of powder metallurgy and forging the perfect combination of Damascus steel on the nature of the pattern is basically two different materials. Bright place is pure snow-ming charcoal iron hardness greater than glass. Dark places of the structure is austenitic plei iron and iron. About the overall content of carbon is between 1.5 ~ 2.0%. In high toughness plei Galtieri evenly spread than glass also hard charcoal iron out the snow. Damascus steel can make a very sharp blade. But also very tenacious and will not break the blade. Damascus steel steel folding pattern and has significant differences. Damascus steel pattern looks more natural rather meticulous black-and-white contrast is also relatively large. In ancient times as a result has the edge on the situation喂毒. A lot of Damascus steel blade has a black phenomenon. Where they are needed most in the black sparkling snow spread out charcoal iron. The ancient Persians to describe it as imaging the night sky, like stars in the beautiful patterns. In addition Damascus folded steel to steel than it is not easy to rust. Down for hundreds of years as Japan did not need to worry about maintenance of the same knife can be bright but not as good as new rust. In fact, the impact of modern manufacturing processes, the Uz ingot production process has been lost, Damascus steel pattern now is a product of modern technology, It should be said that the real has lost a Damascus knife Uz to the forging of steel from the smelting temperature requirements are very harsh, Smelting at a temperature not higher than 1000 degrees, forging must be low-temperature (that is, China's so-called "cold forging"). Plasticity of steel under high temperature is better, the production of swords in general are at a high temperature molding will beat swords. However, if the high temperature Uz steel forging, carbon will be a substantial loss of carbon crystal will be destroyed, Forge should not, therefore, when the temperature is too high (naturally should not be too low), it is difficult to grasp, The necessary skills, experience, labor can be more than any other iron and steel, much lower yield. Uz steel production techniques circulation only in India, Persia and Arab. Europeans as early as the Viking Age through the "road to Greece瓦兰吉亚" import Uz steel, But they are generally formed steel bars, for ingot processed into how Europeans do not understand Article knife. The sixteenth century the Portuguese had been looting a fully loaded Uzi Merchant Ingot India, the Portuguese still know all about the goods, These precious pimple shipped back to Europe for sale, mostly sold to Lisbon and Madrid, senior knife. These knife steel ingot manufacturing these fine knives and other objects, Found no pattern of finished (carbon crystals that have been completely destroyed), mediocre performance, Clearly the Europeans with their own traditional forging process.
Enclosure(chinese translation)
定义：使用乌兹钢锭制造，表面拥有铸造型花纹的刀具，世界三大名刃之一 详细说明： 看到附图里那美丽特别的花纹了吗？ 那就是大马士革钢特有的花纹 大马士革花纹钢刀是欧洲人的叫法， 就像阿拉伯数字一样，它们的原产地都是印度。 在中世纪，印度出产的一种乌兹钢锭，是制作刀剑的顶级用钢， 每年阿拉伯商人都要向印度进口大量的钢锭用于武器制造。 这种钢在铸造成刀剑时表面会有一种特殊的花纹———穆罕默德纹， 所以它是属于花纹钢中的铸造型花纹钢，区别于折叠锻打形成的焊接型花纹钢。 因为花纹能够使刀刃在微观上形成锯齿(肉眼无法分辨)，使得刀剑更加锋利。 大马士革钢刀上的魔性的花纹简直是人工雕琢的自然之美。 因动人的传说和自身的优异性能，大马士革钢制成的刀具，成为刀具收藏界的极品。 近年来有一些公司采用镀锡工艺模仿大马士革钢的花纹 真正的大马士革钢又称为结晶花纹钢.是一种古代粉末冶金和锻造技术完美的结合 大马士革钢刀上的花纹基本上是两种性质不同的材料. 亮的地方是纯的雪明炭铁硬度比玻璃还大.暗的地方的结构是属於沃斯田铁和波来铁. 整体含炭量大约是在1.5~2.0 ％ 之间. 在韧性高的波来铁里均匀散布着比玻璃还硬的雪明炭铁. 使得大马士革钢刀上可以具有非常锋利的刀锋.而且也非常坚韧而不会折断的刀身. 大马士革钢的花纹和摺叠钢有明显的差别. 大马士革钢花纹比较细致看起来比较自然黑白的对比也比较大. 在古代由於有在刃上喂毒的情形.很多大马士革钢的刀刃呈现黑色的现象. 在黑色的刀刃上分布着亮晶晶的雪明炭铁. 古代波斯人把它形容成像夜空中的繁星一样漂亮的花纹. 此外大马士革钢比起摺叠钢来是很不容易生锈. 几百年下来没有像日本刀一样的费心保养却也能光亮如新不生锈. 其实在现代制造工艺的冲击下，乌兹钢锭的制作工艺已经失传， 现在的大马士革花纹钢是现代工艺的产物， 应该说，真正的大马士革刀已经失传了 乌兹钢从冶炼到锻造对温度的要求都很苛刻， 冶炼时温度不得高于一千度，锻造时必须低温（即中国的所谓“冷锻”）。 钢铁在高温下可塑性较好，一般制作刀剑都在高温下将刀剑敲打成型。 但乌兹钢如果高温锻造，碳会大量流失，碳结晶也会被破坏， 因此锻打时温度不能太高（自然也不能太低），很难掌握， 所需的技术，经验，劳力能比其他钢铁要多，成品率却低得多。 乌兹钢刀的制作技术只流转于印度，波斯和阿拉伯。 欧洲人早在维京时代就通过“瓦兰吉亚到希腊之路”进口乌兹钢， 但都是大体成型的钢条，对于钢锭如何加工成刀条欧洲人并不了解。 十六世纪葡萄牙人曾劫掠过一艘满载乌兹钢锭的印度商船，葡萄牙人还算识货， 把这些宝贝疙瘩运回欧洲出售，大多卖给了里斯本和马德里的高级刀工。 这些刀工用这些钢锭制造精致的匕首等物， 发现成品没有花纹（说明碳晶体已完全破坏），性能也平平， 显然欧洲人用的是自己的传统锻造工艺。