This 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.
Crafted and finished entirely with hand tools and traditional techniques, the slender blade profile and thick spine are based on a classical yoroidoshi (鎧通し, armour piercing) tanto design.
The habaki was made from a piece of reclaimed copper bus bar, hammered to shape and soldered in the charcoal forge, and finished with rasps and hand files. The shirasaya (白鞘, storage scabbard) was carved from a piece of figured Japanese hounoki wood and finished with tokusa grass polishing and natural ibota wax. The mekugi was carved from a scrap of black buffalo horn.
Blade construction is muku with a hira-zukuri profile, suguha hamon, and an iori mune. The blade is 6.5″ long, overall length is just over 10.5″, and the overall length when sheathed is just over 11.5″. Accompanied by a hand sewn storage bag made of reclaimed hand-dyed cotton fabric from Japan.
Specifications
長さ/刃長 Nagasa: 5 sun 4 bu (163mm)
元幅 Motohaba: 6 bu 5 rin (20mm)
重ね/元重 Motokasane: 2 bu 5 rin (7.5mm)
反り Sori: muzori
中心/茎 Nakago: 3 sun 1 bu 5 rin (94mm)
柄長 Tsuka: 3 sun 5 rin (93mm)
白鞘 Shirasaya: 9 sun 5 bu (297mm)
形 Katachi: hira-zukuri, iori-mune
刃文 Hamon: suguha
帽子/鋩子 Boshi: komaru
中心/茎 Nakago: futsu, one mekugi-ana, signed near the tip
銘 Mei: hot stamped katabami-ken kamon
拵 Koshirae: none (shirasaya, issaku)
Material: Reclaimed antique horse-drawn carriage steel, copper bus bar, Hounoki, buffalo horn
Separating century-old horse-drawn carriage springs for sorting and inspection.
A small useful segment taken from between a bolt hole and the end of the taper which is too thin to be forged.
Top view of the spine after forging, the mune shape is forged in to preserve as much steel as possible.
A comparison of the size of the original piece with the finished forging, note that the thickness of the spine has doubled from the original spring using a careful technique of upsetting.
Arashiage (filing)
Setting the mune machi and shaping the spine of the tang. (more about the filing process)
Finishing the spine of the tang.
Refining the profile of the tip. (learn about the proper arashiage order of operations)
Ensuring that the hamachi is aligned correctly with the mune and the munemachi. (tanto tang geometry)
Profile complete, bevels are the next step. (tanto bevel geometry)
Using a sen dai (staple vise) and a sen scraper to remove the forge scale and begin rough shaping.
Filing and draw-filing to define the bevels on both the blade and tang.
Clay mixture applied in preparation for hardening the blade. (watch the process of yaki-ire)
Shaping the outside of the saya using chisels and kiridashi. (learn more about the process of making shirasaya)
Drilling the mekugi-ana by hand with a kiri drill.
Shirasaya are thicker and larger than koshirae mountings.
The outside is shaped using kanna handplanes.
Lovely figured hounoki seasoned for about seven years before use, finished with natural ibota wax.
Polishing the Blade
Natural binsui-do stone to refine the shape and remove the last of the arato/kongo-do stone scratches.
Natural kaisei-do to remove the binsui scratches.
Chu-nagura-do more clearly defining the hamon.
Komanagura-do increases the polish level of the ha noticeably.
Suita uchigumori-do to bring out the final details of the steel.
Hazuya and jizuya fingerstones made from uchigumori-do and narutaki-do to even up the surface and add depth.
Boiling water poured over the steel and sashikomi nugui made from satetsu (iron sand) and clove oil applied to darken the ji area.
