Japanese Sword:

History

Art

Science

Imperial Regalia of Japan: Three Sacred Treasures

Sword – Ama-no-Murakumo-no-Tsurugi or Kusanagi-no-Tsurugi– “Sword of the Gathering Clouds of Heaven”– “Grasscutter Sword”– Valor– Atsuta Shrine in Nagoya

Necklace – Yasakani no Magatama– Benevolence– Kokyo (the Imperial Palace) in Tokyo

Mirror – Yata no Kagami– Wisdom– Grand Shrine of Ise in Mie prefecture – "The Eight Hand Mirror"

Initially belong to Sun Goddess Amaterasu– lured out of the cave with the mirror – sword: from Susanoo as a reconciliation gift– sword was in the tail of fire spitting serpent

She gave the regalia to her grandson Ninigi-no-Mikoto– sent to pacify Japan and plant rice– ancestor of the Japanese imperial line

Sword in Japanese History and Mythology

Jade magatama necklace from Japanese burial

Amaterasu“(that which) illuminates Heaven"

Susanoo

“Withering Wind of Summer”

God of the sea and storms

Since 690 A.D. central part of the imperial enthronement– no public viewing, location is unconfirmed– no known photographs or drawings exist– may be not originals

After the WWII Potsdam Declaration on July 26, 1945– fate of the regalia was uncertain – Emperor Showa ordered to secure regalia – undisclosed location, protect "at all cost"

Nara period (710 – 794)Technology imported from China Oldest swords ~ 400 A.D.Straight blade, single cutting edgeFaulty tempering

Heian period (794 – 1185)Improved technologyHorseback fighting Curved blade, up to 4 ft. Hung from the waist Edge down: tachi

Muromachi period (1392 – 1573)Warring States period (Sengoku Jidai)Large demand, decline in qualityDark age of the Japanese sword200,000 nihontō imported to China Development of the uchigatana

– about 24 inches, worn edge up– one hand close quarters fighting– curve is similar to tachi

Kamakura period (1185 – 1333)Golden age of the Japanese swordRetired emperor Gotoba (1180 – 1239)– patron of the finest smiths– forged blades himselfMongol invasion attempts, 1274 & 1281 – footlong tanto, hand-to-hand combat – wider, heavier two-hand tachi

Koto: Old sword

Nanbokucho period (1336 – 1392)Gokaden (Five Traditions)– Bizen– Soshu (Sagami)– Yamashiro– Yamato– Mino

Chokuto (Ken): Ancient sword

The History of Nihonto

Tachi by Ichimonji.National Treasure. TNM

Imperial Japan (1912 – 1945)Mass production for imperial armyGuntō swords: stamped, oil temperedSwords making prohibited after WWII“Lost generation” of swordsmiths

Momoyama period (1568 – 1603)Evolution of the uchigatana– katana (24-30”) and wakizashi (18”)Symbol of power and status Shogunate decree for all samurai to wear daishoSchools are mixed: brighter steel, flashy blades

Meiji Restoration (1867 – 1912)Abolishing samurai class 1971 – edict forcing samurai to cut top-knots1873 – creation of the Imperial Japanese Army1873 – hereditary samurai stipends terminated 1876 – wearing swords is prohibited

Gendaito: Modern sword

Shinto: New sword

1953prohibition is lifted

The History of Nihonto

daisho

Edo period (1603 – 1867 )Tokugawa shogunateStrict class hierarchy – samurai (shi) – farmers (no)– artisans (ko)– merchants (sho)

Appointed “Chief Swordsmith”– grant competency certificates– 910 licensed smiths

Shinshinto swords

Evolution of the Nihonto

Time Line

Time Line

Nippon Bijutsu Tōken Hozon Kyōkai (NBTHK)

“Society for the Preservation of the Japanese Art Swords”Founded in 1960Strict regulations are enforced:

To register the sword with NBTHK:– produced by licensed swordsmith – blade over 6”, hamon, rivet hole in the tang– less than 6”: knifes ( kogatana ), no regulation

Getting a license:– apprenticeship under licensed swordsmith – for a minimum of 5 years

Number of swords:– 2 long swords (>2ft.) and 3 short swords (<2ft.) per month– based on meticulous style of eminent smith Akihira Miyairi

All swords must be registered with the police

NBTHK Competition– one sword per swordsmith – 300-500 swords entered into competition– 15 judges: swordsmiths, appraisers etc.– 2 rounds with covered and open signature– swords ranked first to last– determine the value of the next year swords

– mukansa: above the competition– ningen kokuho: living national treasure

Contemporary Sword: Shinsakuto

NBTHK Tokubetsu Hozon Wakizashi from Mutsu no Kami Fujiwara Kanenobu, a Mino smith in 17th century

Anatomy of the sword

“Cut well” “Not bent” “Not break”Conflicting properties of steel:

– hardness: maintain sharp edge, brittle– ductility: withstand hard blow, soft

Solution – core of the soft steel, shingane– jacket of the hard steel, kawagane– harden only the edge, hamon

habuchi

kawagane shingane

hamon

blade cross section

Properties of the Steel: Fe-F3C Phase Diagram

Pearlite:• α-Fe (88%) and Fe3C (12%) composite• Two-phase lamellar structure

Austenite:• exist above critical (eutectoid) temp. : 727 °C• γ-Fe : solid solution of carbon and iron• Max. [C] solubility = 2.1% , ductile• Face Centered Cubic (FCC) structure

Martensite:• Rapid quenching of austenite• Traps carbon atoms, no time to diffuse out• Body Centered Tetragonal (BCT) lattice

Phase diagram:Equilibrium between the distinct material phases

Steel [C] < 2.1% , Cast Iron [C] > 2.1%

Ferrite:• α-Fe, fairly ductile• Max. [C] solubility = 0.022% • [C] atom ~ 2x interstitial• Body Centered Cubic (BCC) structure

Cementite:• Fe3C, carbide, hard and brittle, ceramic• Orthorhombic crystalline structure

Cementite

Microstructure of the Iron – Iron Carbide Phases

Eutectic transitions: γ-Fe --> α-Fe + Fe3C

Pearlite:• α-Fe / Fe3C lamellar composite• α-Fe matrix • Fe3C stripes

Austenite:• start above critical temperature: 723 °C• carbon content: 0.83%

Martensite:• metastable, kinetic phase • not on phase diagram • needle-shaped grains

Austenite:• start above critical temperature: 727 °C• carbon content: 0.83%

Microstructure of the Iron – Iron Carbide Phases

Pearlite: 88/12 α-Fe/Fe3C

Pearlite + Ferrite:88/12 α-Fe/Fe3C + α-Fe

Pearlite + Cementite:88/12 α-Fe/Fe3C + Fe3C

Microstructure of the Iron – Iron Carbide Phases

Tradeoff : Ductility and Hardness

Austenite:T > 727 °C

[C] < 0.83% [C] > 0.83%Pearlite + Ferrite:

[C] = 0.83%Pearlite Pearlite + Cementite:

Ductility

Hardness

annealing

Martensite:

quenching

Properties and appearance of the steel:- Location on the phase diagram - Subsequent processing & heat treatment

Tatara and Tamahagane: The Nittoho Tatara operated by NBTHK since 1977Three operating cycles during the winter - 7 days / 5 peopleClay vessel: 1.2m (H) x 4.5m (L) x 1.5m (W)10T of satetsu and 12T of charcoal ~ 2.5T of tamahaganeTypical carbon content: 0.6 -1.2 % ( optimum: 1.0-1.2% )

Smelting : Iron ore (Fe2O3) comes as a fine black sand, satetsuThe furnace for smelting, tataraPrimitive and efficient method:

– combine ore and charcoal– pump the air trough bellows– temperature: 1200-1500 0C

Low temperature reduction, no melting Alloys with impurities are not formed, removed with the slag Iron combines with carbon to form tamahaganeTamahagane – “mother of metal” in kanji

The Steel

232

2

COFe2COOFeO COOC

+→+⋅+→+

satetsu

kera

– dense, heavy– silvery color– fine crystallites

tamahagane

Refining the Steel: Oroshigane

Tamahagane - nonuniform, mixture of low and high [C] piecesOutside jacket – kawagane, [C] ~ 0.7-0.8%Inside core – shingane, [C] < 0.5%

Continuous loss of carbon during the processStart forging with high carbon content, [C] ~ 1.0-1.5%

adding [C]

habuchi

kawagane shingane

hamon

removing [C]

3FeCC3Fe →+ CO6 Fe2O3 2FeC 23 +→+

oroshigane

Assembling Steel for Forging: TsumiwakashiT (C) T(F)700 1292

1200 21921300 23721500 2732

oroshigane, [C] ~ 1.0-1.5%

heated to 1200-15000C and flattened into ¼ “ plates

broken into pieces and sorted bright and clear – high [C], kawaganedark and muddy – low [C], shingane

plate with similar to tamahaganecomposition is formed

4-5 lb. of selected pieces stacked and wrapped in rice paper

wafers are fused at 13000C and bar twice the length of the original tamahagane is prepared

Forging: Kitae – Foundation forging: Shita-gitae

Total of 6 folds: cleft, fold, hammer Each fold: 30 min. / 3 heat upsEach fold: 3 min. of hammering Remove impurities, homogenize, air bubbles Consumes ½ of the original tamahagane

make a cleft with a chiseldivide bar into two equal parts

fold the bisected bar, fuse the halves and flatten the bar sorted

repeat the folding, remove impurities and bubbles, homogenize

The way metal is folded will affect jihada and jitetsu - depends on smith’s style and school

the final block is 10” x ¾” x 1 ½ ”, divided with chisel into three equal parts

Initial tamahagane [C] ~ 1.4%0.3% lost in shita-gitae , 0.4% in age-gitaeTypically another ½ of the steel lost

Forging: Kitae – Finish forging: Age-gitae

for katana four steel pieces are stacked an fused

another 6-7 foldsprevent oxidation with clay and straw

Kawagane is ready, [C] ~ 0.7%

Hon-sanmai-gitaeKobuse-gitae

Forming the Steel Stock: Tsukurikomi

Shingane: prepare and shape – long and narrow barFolded about 10 times, drive impurities out Typical shingane [C] ~ 0.2-0.5%

kawagane

shingane

Piercing tip (kissaki) is always made from the best kawagane

Forging temperature: 1300 0C Extremely delicate and vital process

– perfect weld, no voids or gaps– shingane completely covered by kawagane

Forming the Blank, Shaping and Rough Grinding the Blade

Shiage: Preparation to harden the sword edge

– rough grinding and filing– use sen to shave off irregularities

Use carborundum stone to rough grind the blade Shape is well defined, edge is ~ 1/10”

Hizukuri: Drawing the cutting edge: ha-saki

– hummer 6” at a time – yellow (~1100 0C) and cherry red (~700 0C)

Require fast work and precision hammering – overheated: separation of kawagane and shingane– to cold: damage or fracture the sunobe– kissaki , shinogi and mune are formed – blade is “growing” in a straight line– deceptively simple process

A fully formed kissaki, shinogi,and mune from a sunobe

Sunobe: Sword blank with no curve or edge 10% smaller, uniform thickness Define nakago and kissaki

Creating the Cutting Edge: Tsuchioki

Yakiba – hard cutting edge The hardest but brittle form of steel is martensiteHow to simultaneously:

– convert the edge to martensite– keep the rest of the sword as ferrite + pearlite

habuchi

kawagane shingane

hamon

Heat treatment process:– kawagane [C] ~ 0.6-0.7% (optimum, see HRC) – heat the blade above eutectic temperature: 723 °C– fast cooling: austenite -> martensite– slow cooling: austenite -> ferrite + pearlite

Hamon:- martensitic “blade pattern” Habuchi:- transitional zone

Hardness vs. carbon steel carbon content:

No gain, brittleSharp decrease in hardness

Controlling Cooling Rate with Insulating Clay

Tsuchi-dori – clay mixtureStick well to roughened during shiage stage surface

– clay for insulation – charcoal powder for heating control– sandstone (omura) to prevent cracking– school specific ingredients

Thin layer on the edge, thicker towards the backControl cooling rate via:– thermal insulation – increase surface area

Prevent formation of the water bubbles on the surfaceFaster cool down with thin clay layer

Distribution and thickness of tsuchi-dori– will determine hamon pattern – hardness is the objective of the process

Making ashi – literally means “foot” or “leg”– thin tsuchi-dori strips perpendicular to the yakiba– create pearlitic veins on hard martensitic edge – stop crack propagation originated at the edge

Hardening the Edge: Yaki-ire

Yaki-ire – quenching in the cold water – metal is transformed and the sword is born – performed at night to accurately judge the temperature– color of the steel is “like the moon in February or August”– skill and experience – each sword is unique

Draw the sword through the hot coals– slow and steady – first edge up: 10-15 times– then edge down: 2-5 times

Achieve even and uniform color– edge: bright red or orange – back: red or cherry red

Plunge the blade into the water“Tale of the severed hand”

Yaki-modoshi – tempering at 160 0C– reheating and quenching again – relieve the stress, break down martensite crystals

½ of the swords do not survive yaki-ire

Strict attentiveness followed by swift and uncompromised action(zen calligrapher, strike in kendo)

The Science: Yaki-ire

Heat treatment – heating to a high temperature– holding at temperature– cooling down at a specific rate

Steel cracking is the problems during quenching– high rate of cooling: surface cooler than interior – surface forms martensite before the interior– constrains from outer martensitic layer leading to residual stresses

Continuous cooling transform. (CCT) diagram– follow cooling curves – from the top left to bottom right– steel and sample specific

a – austenite

f – ferrite

p – pearlite

b – bainite

m – martensite

CCT diagram for hypoeutectoid steel [C] < 0.8%

Circles – DPH ( diamond-pyramid hardness )

Fast (~10sec): austenite –> martensite Medium (~1min): austenite –> mixtureSlow (~3min): austenite –> ferrite:pearalite

Heat Transfer Modeling: Yaki-ire

Prifile of yakiba-tsuchi

Measured heat transfer coefficient

800 - 400 0C:heat transfer coefficient with thin clayis higher than that of without any clay

Thin clay – nucleation boilingThick clay – film boilingBare metal – film boiling

Inoue Tatsuo, Mat. Sci. Res. Int. Vol.3, No.4 pp. 193-203 1997

Temperature distribution during yaki-ire

Temperature, 0C

0

1

2

3

4

5

10

gyaku-sori: reverse bending ~ 1s sori : normal bending ~ 10s

seconds

Nucleation boiling:– rapid, explosive, formation of bubbles– strong local velocity within the liquid film– increases heat transfer– surface dependant

Film boiling:– continuous layer of vapor covers the surface– insulating effect of the vapor– reduced the rate of heat transfer– Leidenfrost effect

Longitudinal stress distribution and residual stresses

Stress σ, MPa

1

10

4

2

Significant stress in yakibaFracture stress 1600-1700

MPa

seconds

Heat Transfer Modeling: Yaki-ire

Inoue Tatsuo, Mat. Sci. Res. Int. Vol.3, No.4 pp. 193-203 1997

tsuchi: uniform 0.8 mm

tsuchi: uniform 0.1 mm

volume fractions of martensite %

0.8 mm on the back0.1 mm on the edge

Simulation of quenching with different tsuchi distribution

(a)

(b)

(c)

yaki-modoshi

Martensitic transformation:• No long range diffusion • No compositional change• Transformation occurs by shear• Austenite to Martensite → 4.3% volume increase

CBCT

CFCC Quench

% 8.0)( '

% 8.0)( αγ

⎯⎯ →⎯

Adjusting the Curvature: Sorinaoshi

Sunobe is almost straight before quenching During yaki-ire curvature is increased by almost ½” Volume change between austenite and martensiteAdjusting the curve

– straightening by hammering– heating on copper block and quenching– addjust sori locally

(111)γ <=> (011)α’

[101]γ <=> [111]α’

[110]γ <=> [100]α’

[112]γ <=> [011]α’

Bain model – structural transformation with a minimum of atomic motionOne-to-one correspondence between γ and α’ atoms

Two FCC unit cells: - contract by 20% in the z direction- expand by 12% along the x and y directions

Just a Beginning….

Kajitogi : rough polishing Hi : decorative grooves ( add surface area! )Horimono : decorative carvings ( tatoo )Nakago : the tang, filed, never cleanedMekugiana : the rivet hole Mei : the signature, testing, owner etc.

– engraved in the very end– often forged or destroyed – “legend of Kanemitsu”

Polishing: the art by itself– put a sharp edge – reveling the hamon, jihada, jitetsu– bring the sword to life

Habaki: blade is floating in the scabbard (saya)

Shirasaya – simple “white scabbard”– ho tree (magnolia obovata)– glued with sokui, paste from cooked rice – carved with shallow lip for the edge

Saya – kurigata – kojiri– sageo– koiguchi

Tsuba– habaki– seppa

Tsuka– fuchi / kashira

http://www.ricecracker.com/

– makishitasame – tsukaito– menuki

Fully Mounted Sword: Koshirae

Shinto katana. 1600’s. Signed – Suruga no Kami Kunimasa. Yasusada School. Soshu style. Notarehamon. The mounts are original to the blade. Fuchi kashira done in shakudo and gold with a floral design. The tsuba is a large iron sukashi with a design of ginger leaves.

volume fractions ofmartensite %

What Makes Katana a Superior Sword?

Forging– optimal [C] content – folding process

Heat treatment– controlled quenching – martensitic edge

oroshigane

Design– kawagane jacket– shingane core– hamon

Hagakure

A certain swordsman in his declining years said the following:

In one's life there are levels in the pursuit of study. In the lowest level, a person studies but nothing comes of it, and he feels that both he and others are unskillful. At this point he is worthless. In the middle level he is still useless but is aware of his own insufficiencies and can also see the insufficiencies of others. In a higher level he has pride concerning his own ability, rejoices in praise from others, and laments the lack of ability in his fellows. This man has worth. In the highest level a man has the look of knowing nothing.

These are the levels in general. But there is one transcending level, and this is the most excellent of all. This person is aware of the endlessness of entering deeply into a certain Way arid never thinks of himself as having finished. He truly knows his own insufficiencies and never in his whole life thinks that he has succeeded. He has no thoughts of pride but with self-abasement knows the Way to the end.

It is said that Master Yagyu once remarked:"I do not know the way to defeat others, but the way to defeat myself. ''

Throughout your life advance daily, becoming more skillful than yesterday, more skillful than today. This is never-ending.

Extra

The Science: Yaki-modoshi

Tempering – heating below eutectoid temperature– holding at temperature followed by cooling

Tempered martensite: – distribution of fine particles of Fe3C in α matrix – hardness more than pearlite, ductility more than martensite – hardness and ductility controlled by tempering temperature and time

Pearlite

CFeFe 3)( +≠ αCFeFeFe tempering3)( )( +⎯⎯⎯ →⎯′ αα

T<T

Martensite

E

Tempered Martensite

Cold work: mechanical deformation of at relatively low temperatures– increase point defect and dislocations – stronger material

Fe-C diagram:• austenite: FCC γ-Fe ductile• ferrite: BCC α-Fe fairly ductile• FCC unit cell > BCC unit cell

• cementite: 2nd phase [Fe3C] brittle• cementite: [C] is in excess of the solubility limit

• pearlite: two-phase lamellar structure• pearlite: α-Fe (88%) and Fe3C (12%) whiskers

Fe-Fe3C

Eutectic transitions:• Cementite: γ-Fe --> α-Fe + Fe3C• Ledeburite: L --> γ-Fe + Fe3C

Martensite:• tetragonal lattice • rapid quenching of austenite. change in volume • traps carbon atoms, no time to diffuse out

Heat Treatment

A

N

AT

TQ

heating

holding

time

T

Annealing Furnace cooling RC 15 Coarse pearlite

Quenching Water cooling RC 65 Martensite

Tempering Heating after quench RC 55 Tempered martensite

Normalizing Air cooling RC 30 Fine pearlite

Austempering Quench to an intermediate temperature and hold RC 45 Bainite

Continuous Cooling Transformation Diagram for Eutectoid Steel

Martensite:

Austenite

Coarse peralite

Fine peralite

Cooling curvesConstant rate

t (s) →

100

200

300

400

600

500

800

723

0.1 1 10 102 103 104 105

Water quench

Oil quench

Normalizing

Full anneal

Coarse P

P M M+ Fine P

P

T( 0 K

) →

Time Temperature Transformation Diagram for Eutectoid Steel

Austenite

Bainite

Formation of bainite – austemperingBainite: short needles of Fe3C in plates of ferriteLess strong but more ductile than martensite

Upper bainite: Lower bainite:

Austempering

Martempering

References

Front Picture: Blacksmith Munechika (end of the 10th century), helped by a fox spirit, forging the blade kogitsune-maru ("Little fox"). Engraving by Ogata Gekkō (1859–1920), 1873.

http://web.iitd.ac.in/~rajesh/http://www.engr.usask.ca/classes/ME/324/Class-notes/Lecture3-Week11-2005.dochttp://yakiba.com/http://legacyswords.com/fs_gen_sword6.htmhttp://www007.upp.so-net.ne.jp/m-kenji/asj_lecture.htmhttp://www.tnm.jphttp://www.samuraisword.com/nihontodisplay/CUTTING_TEST/Munehiro/index.htmhttp://www.ksky.ne.jp/http://www.thejapanesesword.com/http://www.shibuiswords.com/http://zenkou.com/books.asp/http://www.arscives.com/bladesign/mino_uchigatana.htmhttp://www.geocities.com/alchemyst/terms/terms.htmhttp://www.nihontoantiques.com/jigane_and_jihada.htmhttp://www.arscives.com/historysteel/japaneseintroduction.htm

http://www.youtube.com/watch?v=xzJAUKZGyNQ&feature=relatedhttp://en.wikipedia.org/wiki/Japanese_sword

“Materials Science and Engineering: An Introduction” , 6th Edition William D. Callister, Jr., Univ. of Utah“Phase Transformations in Metals and Alloys” David Porter & Kenneth Esterling Van Nostrand Reinhold Co. Ltd., New York (1981)“The Samurai Sword: A Handbook” Yumoto, John M. Tuttle Publishing, 2002“The Craft of the Japanese Sword” by Leon and Hiroko Kapp and Yshindo Hoshihara; Kodansha America, Inc; 1987“THE JAPANESE SWORD : The Material, Manufacturing and Computer Simulation of Quenching Process”Inoue Tatsuo, Material Science Research International Vol.3, No.4 pp. 193-203 1997“The Forging of a Japanese Katana” Michael Morimoto Colorado School of Mines June 14th, 2004“Samurai: The weapons and spirit of the Japanese warrior” by Clive Sinclaire; First Lyons Press; 2001“The Japanese Sword: The Soul of the Samurai” by Gregory Irvine; Weather Hill Inc; 2000“The Arts of the Japanese Sword” by Basil W. Robinson; Charles E. Tuttle Company; 1971“The Japanese Sword” by Kanzan Sato and Joe Earle; Kondansha International Ltd. And Shibundo; 1983

The Beauty of the Sword

“Cut well” “Not bent” “Not break”The appearance is purely a side effect

Ji – blade surface above hamonHada – “grain” pattern Tetsu – “iron” color, texture, quality

High temperature – metal pastry dough 13-16k layers per inch (214 = 16,384)

Jihada and Jitetsu

masame itame

itame masame mokume ayasugi

Foundation forging: Shita-gitae

Basic Jihada:

Itame:– wood grain, fold alternatively– intermixing of the layers

Masame:– straight grain pattern, fold in one direction– remnants of the original tamahagane wafers

Mokume:– itame with 'whorls’

Ayasugi: – regular wave lines – selectively file away masame pattern

Nashiji Hada:–”pear skin” dense form of komokume

Konuka Hada (Hizen):–”rice bran” coarse form of nashiji

Muji Hada:–”plain” “unfigured” very tight and small

chû = medium Ko = small Ô = large

itame

Ô-itame

Ko-itame mujiitame

Ô-mokume

Ô-mokumeitame-nagare

ayasugi

Jihada

Hamon

Yakiba – the line of the hardened edge Takes on white color when skillfully polished More than 130 documented types of hamon

Kozaemon Yukihira. 1998. Mukansa rank by NBTHK. gunome/notare

Magoroku Kanemoto. circa 1450. “… value rating of 100 pieces of gold." sanbonsugi

Osafune Yukisada. Tachi blade. 1376. choji

martensite

Utsuri

Utsuri – reflection, print, impressionMisty white shadow above the hamonTypical to Bizen blades, very difficult to produce Bright cloudy areas of pearlite + ferrite

Irregular pattern relating with the choji pattern hamon

Pearlite + Ferrite:

Mune is below eutectic temp.Narrow temperature toleranceUniform temperature gradient

NIOI NIE

Hamon

MuneHada

Nioi – vapor, white and mistyNot visible to the eyeLower quenching temperature

Nie – resemble stars in the night skyVisible to the eye, large martensite grainsLonger at higher temperaturePerfected by Masamune

Nie and Nioi

Martensitic crystals embedded in pearlitic matrix

nioi → konie → nie → aranie(smallest) (small) (large) (rough)

Bright martensitic streaks in high carbon areas Kinsuji – “golden lines” parallel to the blade edge Inazuma – “lightning bolt” zigzag or perpendicular to the blade

kinsuji inazuma

“Activities” or “Workings” on the Blade: Hataraki

Large ferrite conglomerates on the tempered steel Different from martensitic particles on the hamonNot the same as jihada, free from layer pattern

jinie → chikei → jifu(fine) (curved lines) (islands)

Shizan by Nakamura Sensei (Ningen Kokuho)

Bugei Tameshigiri - James Williams

Shito

Extra

Until early 1700’s: - very popular amongst higher ranking samurai - even Daimyo lords engaged in tameshi on

corpses by themselves

Mid 1700’s:- otameshi-geisha - professional sword testers- suemono-shi - lower ranking samurai with

recognized swordsmanship skills

Late 1700’s: - Yamada family monopolized tameshi

commissions from the Shogunate - Monopoly lasted for 8th generation

until Meiji Restoration- The family remained ronin in official record

Tameshigiri

S. Takeuchi, Ph.D. Department of Sociology University of North Alabama 2003

Tameshigiri: the purpose of cutting ( “test-cutting” )– closely related to criminal justice in Edo period – public execution ritual – test cutting of convicted felons to evaluate the quality of swords

Suemonogiri: the object/target to be cut ( “fixed (non-living) object cutting” ) – specific form of tameshigiri (typically corpse as stationary target)– skills and abilities of the swordsmen

The swords were rated as:

Saijo O-wazamono - best cutting swordsO-wazamono - excellent cutting swordsRyo-wazamono - very good cutting swordsWazamono - good cutting swords

Modern tameshigiri can be divided into two categories

Shi-zan - test of the swordsman’s skills by cuttingmaki-wara, tatami-omote, and bamboo.

Shi-to - test of the quality of the blades through the use of harder cutting media

Tameshigiri

Shinshinto katana. 1865. Signed by Munihiro. Ryokuruma cut performed by Goto Shintaro

in execution of a criminal

The Legend of Masamune and Muramasa

A legend tells of a test where Muramasa challenged his master, Masamune, to see who could make a finer sword. They both worked tirelessly and eventually, when both swords were finished, they decided to test the results.

The contest was for each to suspend the blades in a small creek with the cutting edge facing the current. Muramasa's sword, the Juuchi Fuyu(10,000 Winters) cut everything that passed its way; fish, leaves floating down the river, the very air which blew on it. Highly impressed with his pupil's work, Masamune lowered his sword, the Yawaraka-Te (Tender Hands), into the current and waited patiently. Not a leaf was cut, the fish swam right up to it, and the air hissed as it gently blew by the blade. After a while, Muramasa began to scoff at his master for his apparent lack of skill in the making of his sword. Smiling to himself, Masamune pulled up his sword, dried it, and sheathed it. All the while, Muramasa was heckling him for his sword's inability to cut anything.

A monk, who had been watching the whole ordeal, walked over and bowed low to the two sword masters. He then began to explain what he had seen. "The first of the swords was by all accounts a fine sword, however it is a blood thirsty, evil blade as it doesn't discriminate as to who or what it will cut. It may just as well be cutting down butterflies as severing heads. The second was by far the finer of the two, as it doesn't needlessly cut that which is innocent and undeserving."

Masamune vs. Muramasa

Muramasa SengoThe founder of the school of sword-making at Ise province. The earliest known work of the school is dated at 1501; the Muramasa school continued into the late 1500's during Muromachi Era.

Muramasa's swords fell out of favor with the Japanese governmentwhen Tokugawa Ieyasu became shogun. It is said that Ieyasu had lost many friends and relatives to Muramasa blades and had cut himself badly with one, so he forbade his samurai to wear bladesmade by Muramasa. Since opponents of the Tokugawa Shoguns would often wish to acquire Muramasa blades, forgeries of Muramasa blades were also often made.

Due to the stigma attached to them, many Muramasa blades had their signature changed or removed. It has also been told that once drawn, a Muramasa blade has to draw blood before it can be returned to its scabbard, even to the point of forcing its wielder to wound himself or commit suicide. Thus, it is thought of as a demonic cursed blade that creates bloodlust in those who wield it.

Masamune Okazaki, also known as Goro Nyudo Masamune (Priest GoroMasamune) is widely recognized as Japan's greatest swordsmith. As no exact dates are known for Masamune's life, he is believed to have worked in Sagami Province during the last part of the Kamakura Era (1288 - 1328)

The swords of Masamune have a reputation for superior beauty and quality, remarkable in a period where the steel necessary for swords was often impure. He is considered to have brought the art of 'nie' to its perfection.

Perhaps the best known Masamune sword is Honjo Masamune, a symbol of the Tokugawa shogunate and passed down from one shogun to another.

Signed works of Masamune are rare. The examples "Fudo Masamune", "Kyogoku Masamune", and "Daikoku Masamune" are accepted as his genuine works. His swords are the most frequently cited among those listed in the Kyôho Meibutsu Cho, a catalogue of excellent swords in the collections of daimyos edited by the Hon'ami family of sword appraisers and polishers.

An award for swordsmiths exists called the Masamune prize which is awarded at the Japanese Sword Making Competition. Although not awarded every year it is presented to a swordsmith who has created an exceptional work.

The LegendOne day, Amakuni and his son, Amakura, were standing in the doorway of their shop, watching the Emperor's warriors return from battle. Although having done so on previous occasions, the Emperor did not give Amakuni any sign of recognition. Having always looked upon these gestures as a sign of appreciation for his efforts and hard work, Amakuni suddenly noticed that nearly half of the returning warriors were carrying broken swords. Determined to make things right, Amakuni and Amakura went about gathering remnants of the swords and examined them. It appeared that the chief reasons for breakage were that the swords had been improperly forged and that the soldiers had struck hard objects, probably armor or other weapons, with them. Once again, the Emperor's subtle yet audible rebuff ran through his mind. Tears filled Amakuni's eyes, and he said to himself, "If they are going to use our swords for such slashing, I shall make one that will not break.“ With this vow, Amakuni and his son sealed themselves away in the forge and prayed for seven days and seven nights to the Shinto gods. Amakunithen selected the best iron sand ore he could obtain and refined it into steel. Working without rest, the two worked at their apparently impossible task. Thirty days later, Amakuni and his son emerged gaunt and weary from the forge with a single-edged sword with curvature.

Legend of Amakuni

Amakuni (天國) is the legendary swordsmith who created the first single-edged longsword with curvature along the edge in the Yamato Province around 700 AD. He was the head of a group of swordsmiths employed by the Emperor of Japan to make weapons for his warriors. His son, Amakura, was the successor to his work. Although there are almost no modern examples of signed works by Amakuni, legend has it that the double-edged katana, Kogarasu Maru, was forged by this man. The true author of this work is not known, though the work bears similarities to works of the various Yamato schools so it is thought to be an early example of work from this province.

The Samurai Sword: A Handbook. Yumoto, John M. Tuttle Publishing, 2002

Undaunted by the other swordsmiths, who believed them to be insane, Amakuni and Amakura ground and polished the new sword. During the following months, Amakuni and his son continued with their work, forging many types of improved swords. In the following spring, there was another war. Again the samurai returned, and as they passed by, he counted over thirty-one swords with perfect, intact blades. As the Emperor passed, he smiled and said, "You are an expert swordmaker. None of the swords you have made failed in this battle." Amakuni rejoiced andonce more felt that life was full and joyous. No one knows when Amakuni died.

Legend of Kanemitsu

Bizen Kanemitsu

He was undoubtedly amongst the foremost makers of his day, and that ever lived. It is recorded that he was born in "ko-an" 1278 and died in "en-bun" 1356 at the age of 83. At the age of 42 Kanemitsu was invited to study with Masamune, the most famous sword maker of his day. Later on his popularity nearly equaled that of Masamune, especially in his native Bizen province. Kanemitsu swords were well known for there exceptional beauty, and functionally. His swords are considered to be the sharpest swords ever known. They were also the subject of much folklore.

“Kabutowari“ - the helmet cutter“Ishikiri" - the stone cutter“Teppo kiri" - the gun cutter

One story sights an incident when during the course of a battle a samurai was cut with a Kanemitsu blade. The cut was so clean, and painless that the man swam across a river in retreat. When he attempted to climb from the water, his body fell to the shore in two half's.

The Samurai Sword: A Handbook. Yumoto, John M. Tuttle Publishing, 2002 http://www.samuraisword.com/nihontodisplay/Hozon/Nobushige/index.htm

The Legend

One day Kanemitsu was enjoying a moment of rest in his shop. He suddenly found himself listening intently to the sound of the chisel of his neighbor in the shop nest door.

Angrily he arose, dashed nest door, and seized the sword on which the other smith had been chiseling the name. “You were putting my name on that sword” said Kanemitsu. The other smith admitted that he had been doing so and apologized. “How did you know?” the guilty one asked. ”Were you watching?”

“No,” answered Kanemitsu, “but I was listening. You used a greater number of strokes that was necessary if you had been writing your own name”

References

Front Picture: Blacksmith Munechika (end of the 10th century), helped by a fox spirit, forging the blade kogitsune-maru ("Little fox"). Engraving by Ogata Gekkō (1859–1920), 1873.

http://web.iitd.ac.in/~rajesh/http://www.engr.usask.ca/classes/ME/324/Class-notes/Lecture3-Week11-2005.dochttp://yakiba.com/http://legacyswords.com/fs_gen_sword6.htmhttp://www007.upp.so-net.ne.jp/m-kenji/asj_lecture.htmhttp://www.tnm.jphttp://www.samuraisword.com/nihontodisplay/CUTTING_TEST/Munehiro/index.htmhttp://www.ksky.ne.jp/http://www.thejapanesesword.com/http://www.shibuiswords.com/http://zenkou.com/books.asp/http://www.arscives.com/bladesign/mino_uchigatana.htmhttp://www.geocities.com/alchemyst/terms/terms.htmhttp://www.nihontoantiques.com/jigane_and_jihada.htm

http://www.youtube.com/watch?v=xzJAUKZGyNQ&feature=relatedhttp://en.wikipedia.org/wiki/Japanese_sword

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