Kumo Katana (T10 Steel & Hitatsura Hamon) - 雲刀

Hand-forged Kumo Katana (雲 — "Cloud") in T10 tool steel with a hitatsura hamon — the rarest temper line pattern in Japanese swordsmithing, covering the entire blade surface in crystalline cloud formations. Hand-polished. Full tang, sharpened. Copper-and-silver tsuba, iron alloy habaki, navy cotton ito over genuine rayskin, lacquered solid wood saya in deep navy with buffalo horn koiguchi and kurikata, silver kashira and kojiri. Includes ornate display stand. T10 steel, hitatsura, real rayskin, buffalo horn — this is the most technically advanced katana in our catalog.

Kumo Katana Specifications

Hitatsura Hamon — Cloud Pattern Across the Entire Blade

Standard hamon patterns (midare, choji, notare) appear along the cutting edge only. Hitatsura covers the entire blade — from edge to spine, nie crystals form across the full surface, creating cloud-like shapes that shift and glow under changing light. Hitatsura is the rarest and most difficult hamon to produce: the clay application during heat treatment must allow crystalline activity throughout the blade's thickness, not just at the edge. Any error in temperature or timing and the pattern fails completely. Historical Japanese swordsmiths considered hitatsura a master-level achievement. On the Kumo katana, the pattern earns its name — 雲 means cloud, and the nie formations look exactly like cumulus clouds drifting across a steel sky.

T10 Tool Steel — Premium Hardness

The blade is forged from T10 tool steel — high-carbon steel with tungsten content reaching 60-62 HRC after heat treatment. T10 holds a sharper edge longer than 1060 (the standard across most of our catalog) and pairs with the hitatsura hamon because the steel's composition supports the full-surface crystallization the pattern requires. The blade is hand-polished after forging, bringing out the hitatsura cloud formations in the steel's surface. This is the same grade used on our Sekiro Kusabimaru and Jin Sakai blades — the premium tier.

Copper-Silver Tsuba & Buffalo Horn Fittings

The tsuba combines copper and silver in a woven-texture oval — two metals creating a warm-cool contrast that reflects the blade's own duality (hard edge, resilient spine). Buffalo horn koiguchi (saya mouth) and kurikata (cord knot) replace the lacquered wood or brass used on most katana — horn is the traditional material found on high-grade historical Japanese swords, denser and more durable than alternatives. The bicolor habaki (brass + copper) bridges the transition from tsuba to blade. Every fitting on the Kumo katana uses a different material, and every material was chosen for a reason.

Genuine Rayskin & Navy Handle

Navy cotton ito wraps over genuine rayskin (samegawa) — not synthetic. The white rayskin diamonds flash through the dark navy cord, providing the natural nodular grip texture that defines quality katana construction. The navy palette runs from handle through sageo to saya, keeping the entire sword in a single cool register. The silver kashira at the pommel and silver kojiri at the saya tip provide the metallic bookends. This is a blade built for collectors who know what real katana forging looks like — and who can tell the difference.

Display

Ships with an ornate black stand with painted dragon-and-peony panel and gold-trimmed feet. The Kumo katana is a standalone centerpiece — the hitatsura pattern alone justifies a dedicated display case. Pair it with the Sekiro Kusabimaru or Jin Sakai for a T10 steel showcase, or display solo where the cloud formations on the blade command full attention. The navy-silver-copper palette works in traditional Japanese interiors, studies, and any space where understated premium materials set the tone.

Frequently Asked Questions

What is hitatsura hamon?

Hitatsura (沸頭) is the rarest hamon pattern in Japanese swordsmithing. Unlike standard hamon that appears only along the cutting edge, hitatsura covers the entire blade surface with crystalline structures called nie. The pattern resembles clouds or smoke and is considered a master-level achievement because it requires precise control of the heat treatment process across the full blade.

What does Kumo mean?

Kumo (雲) means "cloud" in Japanese. The name references the hitatsura hamon pattern on the blade, where nie crystal formations resemble cumulus clouds drifting across polished steel.

Is this Kumo katana sharp?

Yes. The T10 tool steel blade is hand-sharpened and functional. Handle with care, store in the saya, and check local regulations before ordering.

What is buffalo horn?

The koiguchi (saya mouth) and kurikata (cord knot) are made from buffalo horn — the traditional material used on high-grade historical Japanese swords. Horn is denser and more durable than lacquered wood, and is a marker of premium construction.

Is the rayskin genuine?

Yes. This katana uses genuine rayskin (samegawa) on the handle. The white nodular texture visible between the navy ito wrapping is natural rayskin, not synthetic.