Futokorogatana Kaiken Tanto

$2800

A small tanto in futokorogatana kaiken mountings, forged from part of a reclaimed carriage spring.

Out of stock

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Description

Futokorogatana (懐刀) is translated as “clothing fold sword” and describes a type of tanto mounting meant to be carried in the kimono sleeve or fold. Also known as kaiken, this humble style of hidden mounting is usually unadorned with a smooth profile and lacquer finish. This knife would historically be carried for last chance survival situations.

The blade began as a reclaimed piece of horse-drawn carriage spring and was hand forged in a charcoal fire, smoothed with files and a sen scraper, differentially hardened using traditional water quench yaki-ire, and polished by hand with natural Japanese water stones.

Materials for the kaiken style koshirae mounting include Japanese hounoki wood for the handle and scabbard, copper bus bar for the habaki, washi paper, and benigara (crimson lake) stone powder mixed with natural urushi lacquer and crushed tea leaves, and a reclaimed hardwood chopstick for the mekugi.

Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques

Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques

The kaiken tanto was designed to be carried in the fold of a kimono and is characterized by a smooth profile and unadorned lacquered exterior.

Blade construction is muku with a hira-zukuri profile and an iori mune. There is a small ~1mm kizu in the boshi on the omote side. The blade is just under 4″ long, overall length is just under 8″, and the overall length when sheathed is about 8.5″.

Specifications

長さ/刃長 Nagasa: 3 sun 3 bu 4 rin (101mm)
元幅 Motohaba: 6 bu 3 rin (19.5mm)
重ね/元重 Motokasane: 1 bu 8 rin (5.1mm)
反り Sori: uchizori
中心/茎 Nakago: 2 sun 8 bu 4 rin (86mm)
柄長 Tsuka: 2 sun 8 bu 5 rin (87mm)
拵全長 Koshirae: 7 sun 2 bu (218mm)

形 Katachi: hira-zukuri, iori-mune
刃文 Hamon: suguha
帽子/鋩子 Boshi: ko-maru
中心/茎 Nakago: futsu, kuri-jiri, one mekugi-ana, signed near the tip
銘 Mei: hot stamped katabami-ken kamon
拵 Koshirae: kaiken, issaku

Material: Reclaimed antique carriage spring steel, copper bus bar, Hounoki, natural urushi with benigara and tea leaves, reclaimed hardwood from a chopstick


This piece is in a private collection in San Antonio, Texas.


Process Highlights

scroll down or jump to the sections below, more information here:

Blade
Habaki
Tsuka & Saya
Urushi
Mekugi


Forging the Blade

Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
Reclaimed steel from a horse-drawn carriage spring is the raw material for the blade.
Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
The blade is forged by hand in a charcoal fire.
Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
A file is used to clean surface and refine the shape.
Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
A mixture of natural clay, charcoal, and stone powder is used to prepare the blade for hardening.
Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
Immediately after yaki-ire. Watch a blade being hardened using the traditional process.
Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
A test polish on the coarse waterstone reveals the hamon.
Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
Base polishing reveals a ~1mm kizu on the ura near the boshi that cannot be polished out.

Making the Habaki

Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
Silver soldering the habaki in the charcoal forge. Learn more about the silver soldering process.

Carving the Tsuka & Saya

Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
The interior fit is carved first. Learn more about the internal construction of a tanto koshirae.
Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
The halves are rejoined and the outside is shaped with knives and kanna.
Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
Fine dried tokusa grass is used to sand the outside.
Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
Tsuka and saya completed and ready for drilling the mekugi-ana.

Urushi

Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
The tsuka and saya are first coated with a thin wiped layer of fukiurushi lacquer.
Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
When the sealing layer is cured, washi paper is cut and fit to reinforce the wood.
Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
Natural urushi lacquer is used as an adhesive to attach the paper to the koshirae.
Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
After curing several additional layers are added and polished to build up the surface.
Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
Crushed tea leaves are used to build up an ishimeji texture which will be filed down and filled with black urushi.

Making a Mekugi

Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
Hardwood is carved and fit as a mekugi peg before the final lacquer is applied.
Island Blacksmith: Hand forged tanto made from reclaimed and natural materials using traditional techniques
Final layers of benigara (crimson lake pigment) urushi curing before revealing the textured areas by polishing.

3.03022 cm
= 0.1 shaku(尺)
= 1 sun(寸)
= 10 bu(分)
= 100 rin(厘)