The main maker’s mark to look for is the circular katabami ken kamon hot-stamped near the tip of the tang. As a general framework there are phases of seven years each with a different style of marking, although there are some transitional areas.
The date refers to the forging and hardening of the blade, not to the mounting and finishing which in some cases may occur years later, and note that many earlier works and some custom/collaborative pieces were unsigned. Scroll down to see examples of each phase as well as photos of the making of the maru ni katabami ken kamon hot punch.
4. 2018-2024 unsigned/mumei
(2018-2019: no new works due to workshop relocation/construction)
3. 2011-2017 hot-stamped on the tang
- a. kotanto/satoyama: small crossed heart logo 2011-2015
- b. classical tanto: large katabami ken kamon 2014-2017
- c. kotanto/satoyama: large katabami ken kamon 2015-2017
(2004-2010: no new works due to workshop closure/relocation)
2. 1997-2003 hot-stamped on the blade
small crossed heart logo, generally on the ura (back/edge down) side, near the handle
1. 1990-1996 unsigned
a few pieces with hot-stamped large crossed heart logo, on the ura (back/edge down) side, near the handle
4. 2018-2024 unsigned/mumei
mumei is the Japanese term for a sword without signature (mei)
(2018-2019: no new works due to workshop relocation/construction)
3. 2011-2017 stamped on the tang
hot-stamped on the omote (front/edge up) side of the tang, near the tip
3c. 2015-2017 kotanto/satoyama: large katabami ken kamon
3b. 2014-2017 full sized classical tanto: large katabami ken kamon
3a. 2011-2015 kotanto/satoyama: small crossed heart logo
2. 1997-2003 hot-stamped on the blade
small crossed heart logo, generally on the ura (back/edge down) side, near the handle
1. 1990-1996 unsigned
a few pieces with hot-stamped large crossed heart logo, on the ura (back/edge down) side, near the handle
Making the maru ni katabami ken kamon hot punch
The name is explained thusly: “maru ni” means enclosed by a circle, “katabami” are the three oxalis leaves, “ken” are the three double-edged swords in between them, “kamon” is a crest, and a hot punch is designed to imprint onto red-hot steel rather than cold.
Three positive punches were made using hand files, one for the centre circle, one for the sword and heart-shaped leaf, and one to imprint the cross detail into the leaf. After punching the leaf with the cross detail, the centre was punched into the final punch face then the leaf and sword punch was used three times around it to create the negative imprint in the surface of the punch face, finally the circle was shaped around it by removing material. Several heats were required to complete the punching into the tool steel face of an old hammer and the result of the extra punching step (punching a punch) to create the negative is that in use the kamon details are raised up and the background pushed down, creating a positive three-dimensional image.
