Making a Mountain Tanto – Crossed Heart Forge

The wider profile of the mountain style tanto is inspired by a kamakura sword and has a more deeply curved tip (fukura-tsuku) and shorter drop point. The simple and humble mounting style is inspired by the age-old style of farming and foresting tools traditionally used in managing satoyama lands.

Satoyama are the managed forest areas that border the cultivated fields and the mountain wilds in Japan. Historically they provided soil nutrients, firewood, edible plants, mushrooms, fish, and game, and supported local industries such as farming, timber construction, and charcoal making. The interaction of forest, arable land, wetlands, and streams are an important component of the satoyama landscape.

Purchase this knife here or design your own mountain tanto here.

Island Blacksmith: Charcoal forged knives from reclaimed materials.

The tang is constructed in a similar manner to a Japanese sword requiring only a single bamboo peg to hold the knife assembly together. In addition to the sense of beautiful simplicity, this design allows the knife to be taken apart for cleaning, polishing, or sharpening work.

Materials: reclaimed file steel, copper electrical bracket, Nootka Cypress, Black Walnut, cotton cord, natural urushi lacquer, tea leaves, Bamboo

Island Blacksmith: Charcoal forged knives from reclaimed materials.

Forging & Hardening Blade

A worn out and rusted file serves as the starting material for the blade.

A charcoal forge provides the heat to hand forge the file into the shape of a tanto blade.

After forging is complete, the profile is cleaned up with a file. The surface of the blade will retain its hammer texture and the pattern from the original file teeth.

A sen dai style staple vise holds the blade while filing the bevels closer to finished dimensions.

A mixture of natural clay, charcoal, and polishing stone powder forms an insulation layer for hardening.

The clay is slowly dried over the charcoal fire. Note the recurve in the edge to compensate for the upward pull during yaki-ire style hardening.

After yaki-ire, the remaining clay layer is scraped off to reveal the newborn blade.

Forging & Fitting the Guard

The guard is forged from one quarter of a silver-plated copper bus bar washer. The round hole is forged down into the narrow hole for the tang.

The opening (nakago ana) is adjusted by filing until it slips into place on the shoulders of the blade (machi).

Carving the Handle & Scabbard

The halves of the handle block are carved inside to fit the tang.

The placement and fit is done in a specific way for each half, read more about this process: Making a Tanto Takedown Handle

The scabbard is carved inside and rejoined with rice paste glue (sokui).

Once the blocks are dried, the exterior is carved to shape using chisels, a kanna plane, and kiridashi knives.

Lacquering the Handle & Scabbard

The first layers of natural urushi lacquer are applied to seal the surface of the wood and the cord wrapping. Additional layers will strengthen and provide the ishimeji (stone surface) texture when mixed with crushed and dried tea leaves.

The finished Tools for Satoyama Mountain Tanto disassembled into its component parts.

Design your own mountain tanto here.

Island Blacksmith: Charcoal forged knives from reclaimed materials.

Specifications

The blade is just under 7.5″ long and the overall length is about 12″. The spine at the munemachi is about 5mm thick.

Nagasa (blade length): 187mm
Motokasane (blade thickness): 5mm
Motohaba (blade width): 29mm
Sori (curve): uchizori
Nakago (tang): 109mm
Tsuka (handle): 112mm
Koshirae (overall): 340mm

Katachi (geometry): hira-zukuri, iori-mune
Hamon (edge pattern): suguha
Boshi (tip pattern): maru
Nakago (tang): futsu, kuri-jiri, one mekugi-ana, signed near the tip
Mei (signature): hot stamped katabami-ken kamon
Koshirae (mounting): satoyama chisagatana style, issaku