Constant Sub Katana
The Constant Sub Katana is a rare blade — forged not just with steel, but with deliberate complexity.
At its core lies Shihōzume-gitae (四方詰め鍛え), an advanced traditional forging method where the hard steel core is sealed from all four sides with softer layers. This structure offers remarkable balance: strength where it matters, and resilience where it’s needed. It’s a forging style rarely seen today — demanding, precise, and absolutely beautiful in cross-section.
The blade is clay tempered using the time-honored yaki-ire method. A specialized clay mix is applied by hand, then the blade is heated and quenched to create a hard cutting edge with a softer, shock-absorbing spine.
The result? A flowing hamon line, shaped by fire, not acid. Each hamon on the Constant Sub Katana is real — unique, alive, and reflecting the discipline behind its creation.
This katana isn’t built for decoration — though it’s undeniably beautiful. It’s built for balance, control, and lasting strength. A blade that feels quiet in the hand — but decisive in the cut.
Katana Specifications
| Parameters | Specification |
| Item Number | Y-1382 |
| Type | Katana |
| Nagasa Material | Self-produced Steel |
| Nagasa Structure | Four-sided packing ( Shihōzume-gitae/四方詰め鍛え) |
| Heat Treatment | Clay Tempering |
| Hamon | Abunome (あぶのめ) |
| Full Length | 103 cm (40.55 inches) |
| Nagasa (Blade Length) | 70.6 cm (27.8 inches) |
| Tuska Length | 26 cm (10.24 inches) |
| Blade Width | 3.1 cm (1.22 inches) |
| Blade Thickness | 0.75 cm (0.3 inches) |
| Koshirae | Brass, Gilt Silver |
| Tsuba | Brass, Gilt Silver |
| Saya | Wood, Seashells, Cow Horn |
Materials & Craftsmanship
We choose the right steel for each katana—nothing more, nothing less |
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One continuous piece of steel, from blade to handle |
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Through-hardened or clay-tempered, years of experience get it just right |
Hand-Fitted Koshirae
Shaped to follow the katana’s curve, with a secure fit for a smooth draw without slipping loose |
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For centuries, the tsuba has reflected its owner’s taste—and is often the first detail to catch the eye |
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A comfortable shape, a tight wrap—the first step to bringing out a katana’s true power is a firm grip |