Katana Umi 海

Umi means the sea — and this katana was made to carry it. The saya is lacquered the deep blue of open water, the tsuba is carved with waves and tides, and the blade itself moves like a swell drawn into steel. It is a master-tier sword for connoisseurs of traditional practice blades.

Forging & Steel

The blade is forged from T10 high-carbon steel and differentially hardened to raise a distinct, sculpted hamon along the edge. That selective quench is the engine of the blade’s performance: durability and a hard cutting edge up front, flexibility and shock tolerance through the spine, and an edge that lasts through repeated cutting. The temper line is no afterthought here — it is sculpted to read like the line where sea meets sky.

The mounts run with the theme. A high-quality sculpted copper tsuba is carved with wave and tide patterns, the light-wood saya is lacquered blue and carved with a dragon — the sea’s own guardian — and the genuine stingray tsuka is set with copper menuki over two bamboo mekugi pinning a full tang.

Specifications

Dimensions

Is it battle-ready?

Yes. The Umi is a full-tang, differentially hardened T10 katana with a genuine sharp edge, built for traditional cutting practice and equally at home on a stand. At a light 1.2 kg with scabbard it stays fast in the hand. Sold for trained, responsible use.

For more T10 in this register, see the corrugated-hamon Katana Akaryu and the red Katana Ketsueki, or browse the full katana collection.