Japanese Whetstone Glossary

Tennen Toishi Glossary copy.jpg

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Ai-ishi Naori - 合石成り

‘Meeting Stone Strata’ - the literal translation is ‘Synthesis Becomes Stone’. One of the 3 strata that Japanese natural whetstones originate from. Stones from this strata are known to be coarser and softer than those from the Honkuchi or Chuishi Naori.  Hideriyama stones come from this strata. 

Aizu - 会津

A coarse whetstone that can, sometimes, be used for setting bevels on straight razors. This stone was classified in one journal as a type of Dacite, which is a volcanic/igneous stone. It was said to be quarried at Shirodo. 

Aisa - 合さ

Meeting.  This is a layer of stone in the Honkuchi Naori, it is located below Tomae and above Namito. 

Amakusa - 天草

These whetstones are quarried in Amakusa, Kyushu. There are two types: red and white. The white examples are usually finer and slower, the red variety are very coarse (800x-ish) and faster. The grain structure is often uneven and difficult to work with when honing razors.

Aoto - 青砥

Blue  Whetstone.  Ao = blue, To = whetstone. This is a lower to mid-grit type of whetstone. Most known to have been mined in the Tamba region. Aoto can be soft, or somewhat harder. Many of them are soft and coarse, but the harder examples are known to be much finer. In the past, an Aoto’s qualities were assumed to be one way or another based on exactly where it was quarried. Tamba is a word used to generalize the area where Aoto was mined, but there are precise quarry locations that are now almost forgotten, such as Sakei, Kouzaki, etc.


Aratoishi - 荒砥石

Rough Grindstone. Arato (粗砥) stones are used at the beginning of the heavy work when shaping a blade.  These coarse grained stones are used for cutting steel and establishing geometry. A sword polisher will have Arato stones of several types of varying grit; these stones are somewhat coarser than Kongo-do.


Asagi – 浅葱 orアサギ

Light Yellow. This is a color that is confusingly attributed to blue, grey and/or green whetstones.     


Atagoyama - 愛宕山

A mine at Atago Mountain, it’s known to produce large clean whetstones from the Chu-ishi naori.  These stones often have this stamp; 愛宕砿山合砥. Atago-Kouzan-Awasedo. 


Atarazuno hari

Reflective needle, point or dot pattern. This ‘safe’ pattern is said to be a very uncommon characteristic. See Harike for the toxic variety.


Atsu - アツ  

A coarse Mikawa Nagura, usually used for sharpening scissors and similar cutting tools.  


Awasedo -  合砥

Finishing stone.  




Ban - バン  

A type of Mikawa Nagura, one of the usable layers of stone that are quarried, generally used for sharpening edged tools.


Bestu Dai Jou - 別大上  

Superior Selected Grade. One of the Asano quality stamps used on Mikawa Nagura; it indicates that the stone is white with a uniform square shape. Can also be used to indicate Betsu Ōgami, for a large Koppa size Nagura.


Betsu Jou - 別上

Superior grade. One of the Asano quality stamps used on Mikawa Nagura; it indicates that the stone is white with an odd shape.

Binsui – 備水

This is the first stone that follows Arato or Kongo-Do in a sword polishing progression. These are Nakato, or middle-ground whetstones that are quarried at Amakusa on Kyushu. The Binsui-Do is used to remove the scratches from Kongo-Do. An approximate grit range for these stones might be rated as being somewhere between 800x and 2k. 


Botan - ボタン名倉

Peony.  The coarsest Nagura in the typical 3-stone Nagura set used by people honing straight razors.       

Bouoku -茅屋

Thatched cottage; hovel; my humble cottage. The word Bouoku is sometimes used when referring to good quality but unstamped Tennen Toishi.   



Ceiling Nest Plate - 天井巣板

This term refers to stones that come from the seams in the Tenjyou Suita strata.   


Chu Nagura - 中名倉

This is a mid-range stone; In a sword polishing progression, it is the last stone before Koma Nagura Do. High quality Chu Nagura can be used successfully when honing razors or sharpening cutlery.


Chu-ishi Naori - 中石 成り

Stones from this Naori are softer and less fine than those from Honkuchi. They are generally very consistent and of good size. Whetstones quarried at Atagoyama are from this Naori. These stones are described as having the ‘ball’ form, which means they are all one layer. 





Diamond Nagura

Also referred to as a ‘DN’ – a small diamond plate used to generate slurry.   




Enshou - 煙硝  

Firecrackers. This characteristic is the result of sulfur in the stone; usually seen as blue/black spots or lines. This can also be referred to as Ao-Renge. It’s been said that the sulfur in the stone can cause a discoloration in certain types of steel.  



Gokujyohin - 極上品

Best quality - a stamp seen on some Tennen Toishi.

Gotogi – 合砥

‘Layered, or to be together’ –  many Japanese Natural Whetstones, such as those from Tomae strata, were formed with layers that can be seen on the sides of the stone. 


Goma - 胡麻

‘Sesame Seeds’ - These are small black dots that look like sesame seeds. Many people believe this pattern indicates that the stone will have good speed. Goma can be ‘safe’ or ‘toxic’; if they are too hard, they can scratch a fine edge. 


This is a deep seam in the Tomae strata; it has been said to be located next to the Aisa strata. However, some experts disagree and say it is a seam in Aisa that it just below or next to the Tomae strata. Toishi from this seam can be hard or very hard as well as somewhat softer than hard - but usually not very soft.  



Ha - 刃           

This is the hardened steel section of a blade that forms the cutting edge.

Habiki -刃引き  

pulled edge,  meaning - a sword with a dulled or blunted edge. 

Habutae - 羽二重 

Fine Silk. A color characteristic attributed to certain very white Suita, sometimes also called ‘rice cake’.

Hachi-mai-sō -八枚層

8 layers. Meaning – this refers to the 3rd deepest strata in the Hon Kuchi Naori. It is directly below Tenjyou Strata, and just above Senmai Strata.

Hagane - 鋼   

Steel. Also called kotetsu. Literally, this is the harder ‘edge’ steel that is supported by an outer layer of soft Jigane.


Hamon - 刃文

Blade Pattern.  On a sword, this is the outline of the hardened zone known as the Yakiba, which terminates at the cutting edge or Ha.  


Hakka - 八箇

This was a whetstone mine that produced many good stones. Generally speaking, they are usually softer and coarser.

Hanko -判子

Seal, a stamp used in lieu of a written signature.



This term is used to describe what can be described as a toxic needle pattern. This is a toxic inclusion and it can scratch the steel and possibly damage an edge.

Hatanaka - 畑中

This is a family name that belongs to the final owners of the Nakayama mine. They are still in business selling Tennen Toishi.

Hazuya - 刃艶 

This is a very thin slice of Uchigumori stone that is fixed to paper.

Heikin kōdo -平均硬度

The average hardness


Hideriyama - 日照山

A whetstone mine known for producing good quality stones that are generally expected to be softer and more coarse that hones from the eastern mines.   


Higashi Mono

Eastern mines of Kyoto, e.g. - Narutaki Mukoda, Nakayama, Okudo, Ozuku and Shobudani.

Higonokami - 肥後守

A traditional woodworkers knife with a laminated steel blade and brass scales.

Hikikoro - 抽 轆

Translation (slang):

Hiki - Pulling the saw/taking out from the mine.

Koro – roller, pully – shaped like a ball, (obscure Kun-Yomi term). 

The term "Hikikoro" is a slang term used by miners; it refers to Koma shaved by hatchet.  The weight is about 200g. 

According to Mr. Kosuke Iwasaki, Koma was not cut with a hand saw, it was shaved with a hatchet at the mine area; the other Nagura were cut with a saw after it was taken to the village near the mine. Also - see – Kiridashi

Hinoki -檜

This is one type of Japanese cypress used for making a Toishi Dai.

Hin Shitsu Yuu Ryou - 品質 優良

Excellent Quality Product. This stamp is sometimes seen on finishing stones.  

Hodoyoi Kata - 程よい硬

Reasonable hardness


Hon-kuchi Naori - 本口成り

"Main Opening Strata", the literal translation is ‘Becomes the Mouth’. This is one of the three stone formations that Japanese whetstones originate from. The stratum in this formation are known for producing the hardest and finest stone.


Honyama – 本山

True Mountain. These Kanji are also used for ‘Honzan’. Originally, Honzan and Honyama were terms used specifically and only when referring to a natural whetstone from Nakayama or Shobudani. In more modern times, they are used generically to mean any natural whetstone.   

Hosome -細目

Break Down. Used when describing what happens when working slurry on a Toishi, as it refines. 




These coarse whetstones are Nakatoish, or Chu-Shiage stones. Reportedly, the blue-ish examples are finer than the white ones. There has been some speculation as to the origin of these stones; both Nigata and Kyushu have been referenced as the source.

Imo-ishi - 芋石

Potato Stone. This term refers to Japanese natural whetstones that are homogenous, without any layering. These Toishi can be used on any side; many Aoto are potato stones.


Iromono - 色物

Colorful Laundry. This characteristic shows as abstract splashes of color; red, pink, violet and possibly other colors mixed in as well. This is seen most often in softer Kiita stones. 



Ji - 地 

This refers to the section of the blade between the Hamon and the Shinogi.   

Jigane - 地鉄             

This is the softer outer layer of steel that supports the harder Hagane.     


Jinzou Toishi - 人造砥石

Synthetic whetstone.

Jizuya - 地艶 

This is a type of final polishing stone; usually quarried at Narutaki. It is used to polish the ji. 

Jyunhonyama Awasedo -  純本山合砥

Real authentic finishing stone, this stamp is found on some Awasedo.

Junzo Kawashiro Nagura - 純三河白名倉

Another name variation for Mikawa Shiro Nagura.



Kaeri  – カエリ

Burr. A small ‘curl’ of steel coming off the apex of the cutting edge.  

Kaiji Oshi - 鍛冶押

Rough Polishing. This is the final stage of the smiths work. At this juncture, the blades’ lines and basic geometry are established. This allows the smith to inspect the steel to ensure the absence of cracks or defective welds.  Also called Kajitogi. The smith will also add his signature, drill the hole for the Mekugi, and add any decorative work if needed. After this, the blade will go to the polisher.  

Kaisei - 開成

This is the 3rd stone in a modern sword polishing progression. Known as Kaisei-Do, this stone removes the scratches left by Binsui-do and it precedes the finer Chu-Nagura-Do.  An approximate grit rating would be 1k-4k. 

Kamaboko - 蒲鉾

Loaf Shape. Sometimes used to describe the shape of the stones used by Togishi for polishing Nihonto.

Kamisori - 剃刀   

Razor. Usually indicates a Japanese-style straight razor that does not fold into scales.  

Kamisori-to - 剃刀砥

Razor Strop


Kamisorido - 剃 刀 砥

Razor Sword Whetstone. This quality stamp can be found on stones that are hard/fine and selected for honing razors, or stones that are cut smaller for use as razor hones.


Kan - 環巻

Ring Winding. A pattern in the stone that resembles the age rings in a tree. Sometimes, very pronounced Kan rings can be invasive and scratchy. The darker rings can be of a different density that imparts a change in the feedback on the stone. However, most of the time, Kan is not invasive and safe to hone on.

Kanato-ishi - 金砥石

A flat metal plate for sharpening woodworking tools; a small amount of abrasive emery powder was sprinkled on the plate.

Kata-ishi - 硬石

Hard stone

Katai ishi - 硬い石

Harder/solid stone

Katakuchi - 締まっている硬口

Hardness ports are tightened.. This term is used when describing the hardness of a toishi hat is very hard.



This s a hairline inclusion that is toxic. It can be felt under the blade when honing; it contains very hard particles that can damage the edge. 


Karasu - カラス or 烏

Crow. This is an abstract pattern that resembles a blurred flock of crows flying against the sky. Dark Karasu spots can possibly be scratchy; meaning, the darker spots in some Karasu patterned stones may scratch certain steels. Additionally, very lightly patterned Karasu pattern are highly sought after. This pattern is associated with stones from deeper layers, such as Aisa.

Kawato - 革砥

Leather strop used for final finishing a sharpened edge.

Keppan -血斑

Blood Spot, often used to describe a red splotch of color in a Kiita Toishi.



These are hairline inclusions that are safe to hone on. They contain soft particles that will not damage the edge. They can take on water though, and over time they can cause the stone to split along the line.


Kiita - 黄板

Yellow Plate.  - a stone showing a pronounced yellow coloration is called "Kiita.  They are highly sought after, and are generally seen being a bit softer than most Asagi stones, but some Kiita are exceptionally hard. 


Translation (slang):

This term refers to the leftover pieces of Koma that are smaller than "Hikikoro"; their weight is usually around 80-100 g.


Kizuyama - 木津山

One of the eastern whetstone mines in Kyoto.


Koma  - コマ 

 ‘Fine’ – Koma Nagura is the finest and usually the most expensive of the Mikawa Shiro Nagura. In a sword polishing progression, Koma follows Chu, and it is the last step before the final polishing steps.

Kongo Do - 金剛砂石

Emery Whetstone. This is most often the 1st and coarsest stone used in sword polishing. An approximate grit rating could be 80-220x. This is primarily used for the rough shaping of a sword’s geometry, or heavy repair work.  


Koppa - 小端

Small End. – this term is used to describe a larger or small stone with an irregular shape.  It is often used to describe a small razor size stone also. Koppa are usually less expensive options than their bench-stone sized brethren. 

Koukyuu - 高級

High class or high grade. 


Kouzaki - 神前

This was a mine in the Tamba area where Aoto were quarried; the stones from this location were generally harder and finer than stones from the other mines.

Kyoto - 京都府

Kyoto-Fu. Kyoto is a prefecture in Japan that is located in the Kansai region on the island of Honshu. The capital city is also named Kyoto. The prefecture of Kyoto is where many of the most famous whetstone mines were located.


Kyoumen-Shiage - 鏡面仕上げ

Mirror Finish.  This is a self explanatory term used to describe a very high polish on the bevel. 


Kyou-To Toku-San - 京都特産

Special Product of Kyoto – a stamp seen on the tops of Tennen Toishi.  

Kyushu - 九州

A Japanese region/island; Amakusa & Binsui Toishi, and Tsushima Black Nagura  are quarried here.



Marine Steel - 舶来鋼

Marine steel is an alleged ‘rust resistant’ variant of Carbon Steel, often said to be a precursor to stainless steel. It wasn’t very rust resistant though. Often incorrectly called ‘imported steel’ – which is the Chinese translation of the Kanji. 



市印 -  Maruichi jirushi, Maruichi brand.

特撰 - Tokusen,  especially selected.

There is a story claiming that this stamp was used by Kato-san when he ran the quarry at Nakayama.  There is another story claiming that not all stones with this stamp are from Nakayama. For whatever reason - there doesn’t seem to be any hard data on this stamp’s origin, use, or history. 

 Maruka - ㋕正本山         

Maruka Shou-Honyama. A stamp that is found on the ends of stones quarried at Nakayama. This was used by Hatanaka, the circled ‘Ka’ character paid homage to Kato-san, the previous owner of the mine. The translation of ‘maru’ is circle; the circled Ka translates to Maru-Ka or Maruka. the rest of the characters are Shou-hon-yama which mean ‘Real Original Mountain’. 

Masame  - 柾目

Straight grain. Japanese whetstones cut across the grain, so the lines show on top of the stone’s working surface.


Maruoyama - 丸尾山

A western mine in the Oouchi district; known for stones quarried from the Hon-Kuchi and Ai-ish Naori. They have 3 quarries at Maruozan (丸尾山) mountain.   


Mejiro - 目白

White Nagura or ‘White Eye’. This is a mid-range Mikawa Shiro Nagura.  

Mizu - 

Water. This is a color characteristic attributed to grey/blue Asagi stones.


Mizukihara - 水木原

A western Kyoto mine, located in the same mountain as Ohira.


Mokume – 木目

Wood Grain. A pattern that resembles the grain found in wood.     


Momiji - 紅葉

Translation: Autumn Leaves. Often said to be specifically ‘maple leaves’. This is a pattern that looks like leaves in/on the stone. Many say it is specific to Suita stones, but I have seen it used to describe a leaf pattern on Tomae stones also. An alternate term is Kouyou.  


Mikawa Shiro Nagura

These Nagura are quarried in the Aichi prefecture at the Mikawa Nagura Mine - 純三河白. When honing razors, these stones are used to create an abrasive mud  or slurry on a harder finishing stone. Mikawa Nagura can also be found cut as full sized bench stones, these are used for polishing swords, and sharpening many types of edged tools, including razors. 

There are 12 layers of stone at the mine, but only 8 can be used for sharpening. Botan, Tenjyou 1, Tenjyou 2, Mejiro, Koma, Atsu, Ban, Yae Botan. For honing razors, the most commonly used are; Botan, Tenjyou and Mejiro. Koma is also used for razors but less frequently; it is very rare and expensive. Historically, the finest quality stone from Mikawa carry the Asano quality stamps. 

Mizu Asagi - 水浅黄

Water Shallow. Usually, this term is used to describe a blue/grey color that is reminiscent of shallow ocean water. Technically, the color is mostly green with a hint of blue. But when used to describe Awasedo, the meaning can be interpreted to mean a variety of similar hues. 




Nagura - 名倉

Correcting Stone. This can mean any stone that is rubbed on top of another stone to create slurry or to smooth out one or both surfaces. See Tomo Nagura, Chu Nagura, Mikawa Nagura and Diamond Nagura.

Nakatogi - 中都議

Medium Polish. This term seems to be used mostly in the carpentry trade. It refers to the middle stages of sharpening, up to and including the pre-finish sharpening.  


Nakatoishi – 中砥石

Medium Grain Whetstone. These stones are used for the mid-range sharpening/polishing work, which is relative to the type of edge being developed. When sharpening swords and other heavier cutting tools, Kasei, Binsui, Chu Nagura Do, Uchiguimori and Koma Nagura Do are commonly used as Nakatoishi.


Namito - 並砥

This is a deep strata in the Hon-Kuchi naori; it is located below Aisa and above Hon-Suita. These stones are often hard, fine grained and very consistent.    


Nakayama - 中山

This is arguably the most famous eastern whetstone mine. It was located at Atago Mountain.  


Namazu - なまづ or 癜

This is a pattern seen in Japanese natural whetstones. It is usually comprised of irregular lighter-colored blotches, streaks or spots on the surface. 


Naori - 成り

Strata. See Hon-kuchi, Chu-ishi, and Ai-ishi Naori.


Narutaki - 鳴滝

This can refer to the mine, or the region where the Higashi Mono or Eastern Mines are located. 


Nashiji - 梨地 or なしじ

Pear-like. This is a ‘pear-skin’ pattern found mostly on Kiita stones from the Tomae strata.  Many believe that Nashiji indicates superior cutting speed but whetstone authorities claim it is only a visual aesthetic.  

Nihon Kamisori You - 日本剃刀用   

For Use with Japanese Razors – a stamp seen on the top of finishing stones.


Nishi no Yama  - 西の山

Mountains in the west. Refers to the western mines of Kyoto, e.g. – Tanba, Ohira, Mizukihara, Shinden, Okunomon. 

Nenrin Hada - 年輪肌

Annual Rings Skin. This term is used to describe a detailed pattern that looks like the growth rings seen when you cut through a log or tree.




Ohira - 大平

An active western Kyoto whetstone mine, well known for Awase, Suita and Uchiguimori.


Okudo - 奥殿

This is a semi-active eastern (Higashi Mono) Kyoto whetstone mine that is best known for the most highly coveted Suita in Japan.


Okunomon - 奥ノ門

This western Kyoto mine was located next to Ohira.

Omote - 表 

The signature side of the sword’s nakago, it is the obvious side of the blade that faces away.  

Oomura 大村

A whetstone mine on Kyushu, this location was known for producing sandstone Aratoishi. 


Otoyama - 音羽山

This whetstone mine is known for producing Suita.

Ōuchi - 大内

A Western Mine known for softer coarser bench stones of good quality. 


Ozuku - 大突

This was one of the famous eastern mines in Kyoto.  


Ozaki - 尾崎

A whetstone mine in Kyoto. 




Renge - 蓮華

Lotus Blossom. This coloring/patterning is specific to Suita stones. Usually seen as a red, pink, brown or black pattern of fine lines. This visual aesthetic has no positive affect on sharpening capabilities; some say that the presence of Renge indicates a reduction in cutting strength. 



Saeki - 佐伯

This location is known mostly for the production of soft coarse stones. Some examples are harder and highly sought after.


Sai Jou Kyuu - 最上級

Highest-grade. This stamp can be found on finishing stones. 

Saiku - 細工

Craftsmanship, but can also mean trick.

Saiku Hira Kanna - 細工平鉋

Plane for very fine work

 San  -サン

San size is a form-factor for Japanese Natural Whetstones. They are long and thin, usually around 200 x 50mm or similar. Often, these San-size Toishi are end cuts removed from larger slabs that were portioned into full-size bench-stones.  

Semai- 狭い  


Shiage – 仕上げ

Finish. These are the final stages of sword polishing.  


Shiage Toishi - 仕上げ砥石

Finishing Stone. These stones are usually fairly hard and fine – they are the last stones in the progression and used for the final polishing stage.

Shimari-gimi - 締り気味

Tight feeling of interference. This term is used to describe the hardness of a whetstone that is above average hardness, but not quite ‘very hard’.


Shinden - 新田

A Western Kyoto mine known for producing highly prized Suita.

Shinogi - 鎬   

This is the ridgeline on the blade where the Mune meets the beveled Ha.

Shiro - 白

White, as in Shiro Suita /白巣板

Shiro Suita - 白巣板

These deep-stratum Suita are usually hard, fine and fast. They are exceedingly rare, highly coveted and very expensive. 


This whetstone mine is connected to Ozuku.


Shitaji – 下地

Ground Material. These are the lower stages of sword polishing.  


Shou Hon Yama - 正本山

Real Original Mountain. This stamp can be found on finishing stones.  Also reads as Shou – Hon – Zan.

Shouhonyama Honkakuhin - 正木山木 格品

Correct Original Mountain Original Source.

Basically, this should infer that the stone comes from the area around Kyoto where the original Honyama were mined.


Stratum - 層

A layer of whetstone; Tomae and Aisa are two strata in the Honkuchi Naori.


Su - 巣

Nest. These are small holes that were left behind by escaping gases when these stones were being formed in the earth’s crust. They are associated with Suita stones, but they can be found in other layers also.


Suita - 巣板

Nest Plate. Suita stones come from 3 different stratum.  Most, but not all, of them have ‘su’ – small holes or pockets created by escaping gas when the stones were forming in the earth’s crust.  Under close inspection,  su can resemble a hive or a nest. Suita without su are known as Sunashi Suita.


Sujimono - 筋物

Muscle Of. This word references stones with a lot of Suji. Often, but not always, this characteristic is an indicator that the stone is inferior.   

Suminagashi - 墨 流 し

Floating ink. This is the process of marbling paper with ink or dye that is floated on water. A stone that has a similar type of pattern may also be referred to as Suminagashi.

Sunashi - 巣なし

No Nest. This is a type of Suita stone that has no su.


Suji - 筋

Muscle. This refers to lines in the hone, some of which may be ‘safe’ while others can be ‘toxic’ Kesuji and Kanesuji.


Sword Grade - 刀剣用

Sword with Knife. This Asano quality stamp can be found on large pieces of Mikawa Shiro Nagura; it infers that the stone is high quality and good for use when polishing swords. 



Tamago -

Translation: Egg. Used to describe the color of stones with a specific type of mottled creamy yellow coloring.

Takao - 高雄

This whetstone mine in Kyoto was well known for producing Awasedo.


Tajima-To - 但馬砥

Medium grit whetstone.


Takashima - 高島

This  whetstone mine is located northeast of Kyoto. Stones from this location come from the Hon-Kuchi Naori, and they are generally very consistent and fine but a bit soft.


Tamahagane - 玉鋼

Jade Steel. A type of steel used by master sword smiths in Japan.

Tamamoku - 玉目

Circular Burls. This is a rare and beautiful Toishi pattern that emulates the figuring in Tamamoku cedar.

Tamba - 丹波国

Tamba no kuni. This was an old province in Japan, this area is where many Aoto Toishi were quarried. Sometimes spelled “Tanba”. 

Tamba Kei - 丹波系

Tamba family, refers to the general area where stones are quarried in and around Tamba. 

Tengu-do - 天狗砥

Tengu whetstone. This is a coarse stone with red stripes. It is similar to, but more aggressive than, Amakusa white.


Tenjyou - 天上

Heaven or Sky. A mid-range Mikawa Nagura, also spelled Tenjyou.


Tenjyou Suita - 天上巣板

A shallow strata or layer in the Hon-Kuchi Naori.


Tenjyou Tomae

A stone strata located in the Ai-Ishi Naori.


Tennen Toishi - 天然砥石 

Natural whetstone.

To - 

Whetstone or Grindstone. 


Togidoro - 砥泥    

Stone slurry mixed with steel, aka - swarf .

Tojiru -閉じる

This term refers to the lubricating abrasive paste, or slurry, made with Uchiguimori. It is often loosely translated to mean ‘juice’, when referring to any slurry on any Tennen Toishi.

Tokusenhin - 特撰品

Choice goods, this stamp can be found on some Tennen Toishi.


Tomae - 戸前

This is the largest strata in the Hon-Kuchi Naori; there are 48 veins of Tomae.  It is found above the 4 layers of Aisa, and below the 2 layers of Senmai strata.

Toishi - 砥石



Tokkyuu - 特級  

High grade. One of the Asano quality stamps used on Mikawa Nagura; it indicates that the stone is striped with an odd shape.


Tokkyujou - 上特級

Superior High Grade. One of the Asano quality stamps used on Mikawa Nagura; it indicates that the stone is striped with a square shape.

Tomen - 砥面

Abrasive surface; a whetstone’s working surface.


Tomo Nagura - 共名倉 or ともなぐら

Total Nagura. This term refers to a small piece of stone used to raise abrasive slurry on the Honzan.  

Tomoto Kyho Togi - 共砥

Co-Abrasive. Also translates to – Paired Hone.

Torato - 虎砥

Tiger Whetstone. This term is often used when referring to Amakusa Toishi that have reddish ‘tiger’ stripes. 


Tsushima Black Nagura

A whetstone quarried on the island of Tsushima, off the west coast of Nagasaki. It is a mid-range whetstone that produces slurry that breaks down to a very fine degree.

There are two types of Tsushima Black; Ocean and Mountain; the Ocean Tsushima Black is quarried underwater. 




Ukeai Junshou Honyama -  請合純正本山  

Guaranteed Real Nakayama. This stamp can be found on the top of whetstones.  


Uchiguimori - 内曇 or 天上巣板

A specific type of Suita that is traditionally mined at Ohira. There are two types, Hato and Jito; they are used for bringing up the polish to accentuate the Hamon on a sword or the steel’s patterning on a knife. Often used as Hazuya.  

Uchigumori Hato - 内曇刃砥         

This softer Uchiguimori is used to bring out details in the ha.  


Uchigumori Jito - 内曇地砥

This harder Uchiguimori  is used to bring out details in the Ji.

Umaji - 馬路山

This Nishi-mono whetstone mine was located on the west side of Mt. Atago along with Oohira and Shinden. Generally, but not always – this location was known to produce softer stones from shallow layers. 

Umegehata - 梅ヶ畑

A valley area in Kyoto Japan, Nakayama and other famous mines were located here.   

Uma Kawa - 馬皮


Ura - 裏

The secret side of the sword that faces inward, toward the body    


Wakasa - 若狭 

This is a whetstone mine at Miyama Mountain. Some Wakasa are very hard and fine, but many are a little bit soft. 


Yaginoshima - 八木嶋  or 八木ノ嶋

This whetstone mine is located east of Ohira and known for producing good Suita.


Yake - 焼け or やけ

Burnt. This is a dark orange/deep umber coloring often seen on Suita but can be present on any Tennen Toishi. When and area of stone shows very dense and hard Yake, it can be problematic to hone on and it can scratch the blade. This word is also used to refer to any pronounced splashes of color on a stone. 

Yakiba - 焼き刃  

Tempered Blade. This is a sword term; it refers to the hardened, tempered area from the top of the Hamon to the edge

Yamashiromate - 山城銘砥

Yamashiro (Mountain Castle) Inscribed Whetstone.  This is a 330Mate Stamp; said to mean that the stone comes from the Yamashiro region in central Kyoto.


Yari Kanna - 鑓 鉋

Japanese woodworking plane

Yasuki Steel - ヤスキ鋼

YSS is a special designation given to specific steel types produced by Hitachi. Some razor manufacturers have referred to these steels as ‘Tamagahane’.  I have to assume that this was done, mostly, during a period of time when very little real Tamagahane was being manufactured. While YSS was created using the same iron sand, it is not Tamagahane steel; it can be White 1/2, Blue 1/2/Super or Yellow Paper steel. Because Yasuki/Yasugi steel is made in Japan, it is referred to as nihontetsu 日本鉄 . 


Yae-Botan - 八重ボタン   

A coarse Nagura quarried at Mikawa. This layer is known to sometimes have sand layers and quartzite inclusions. These Nagura were usually faster and coarser than Botan. 

Yuge - 弓削

This is a whetstone mine in northern Kyoto. This source is known fo softer high- quality stones from Tomae strata; 弓削 戸前 = Yuge Tomae.


Yuuryou Shiage To  -  優良仕上砥 

Superior Finishing Hone. This quality stamp can be found on Awasedo.

© Keith V Johnson 2014 - 2018