T10 Carbon Steel Katana with Koi-Painted Blue Saya and Chrysanthemum Tsuba

The blade is forged from T10 carbon steel, a high-carbon tool steel valued for its edge retention and fine grain structure. A genuine hamon runs along the length of the polished chrome-finish blade, the result of differential heat treatment during the forging process. At 40.5 inches overall with a blade width of 1.26 inches and spine thickness of 0.28 inches, the proportions follow classical katana geometry. The full-tang construction extends from tip to pommel, giving the piece solid structural integrity. Total weight is 3.2 lbs, balanced for display handling.

The tsuka is built over the full tang and wrapped in dark blue ito cord in a traditional diamond (hishigami) pattern over white PU ray-skin samegawa. The wrap sits firm and even, with no loose sections at the kashira or fuchi. A matching blue sageo cord is attached at the kurikata, completing the handle-to-scabbard color continuity.

The gold-tone alloy tsuba is cast in a chrysanthemum motif - a classic Japanese symbol of longevity and imperial elegance. The raised petal relief is detailed on both faces of the guard, and the gold finish coordinates with the brass habaki seated below it. This is one of the more visually distinctive elements of the koshirae, pulling the deep blue and white palette together with a warm metallic accent.

The saya is where this katana makes its strongest visual statement. Crafted from hardwood and finished in a multi-layer piano lacquer, the scabbard shifts from solid deep blue at the tip into a white ground panel near the mouth, where a hand-painted koi fish scene unfolds - red and orange koi surrounded by lotus blossoms, flowing water, and green foliage rendered in vivid detail. No two sayas will be painted identically. For collectors drawn to Blue Samurai Sword designs, this koi lacquer finish is among the most elaborate available at this construction tier.

This katana is built on Carbon Samurai Sword foundations - T10 steel, full tang, real hamon - and finished with a koshirae-style mounting that treats every component as part of a unified aesthetic. Overall length 40.5 in, shipping weight 3.4 lbs. Sword stand not included.