Katana Golden Torrent Kobuse Blade Kogane Shizuku Koshirae 金流

Clay Tempered Full Tang Shinken (真剣) | Golden Torrent Katana: TangGu (湯谷) Kobuse Blade (甲伏造) + TangGu (湯谷) Kogane Shizuku Koshirae (金雫拵)

The blade is forged in Kobuse-zukuri（甲伏造）construction, where a hardened steel jacket surrounds a softer core to achieve both resilience and cutting power. The surface reveals Masame-hada and Mokume-hada（柾目肌交杢目肌）, displaying fine straight grains mixed with swirling woodgrain patterns through orikaeshi-tanren（折返し鍛錬）folding. Along the edge runs a distinctive Gunome-midare hamon（互の目乱れ刃文）, formed by meticulous clay tempering（覆土焼入れ）.

The fittings are crafted with minimalist elegance. The Mokko-style Tsuba（木瓜鍔）, forged from blackened iron（鉄地）, bears a four-lobed silhouette with an openwork axe motif — practical in defense yet symbolic in design. The fuchi-kashira（縁頭） are smooth, polished copper with no ornamentation, emphasizing simplicity. A pair of arrowhead-style menuki（目貫）, cast in matte white copper, rests beneath the grip. The habaki（鎺） is made of red copper with a clean, polished finish.

The tsuka（柄） is wrapped in high-quality green silk ito（絹糸） using hishigami（菱紙）reinforcement, over premium natural samegawa（鮫皮）, creating both comfort and symmetry. The saya（鞘）, made in the uchigatana style, is fitted with buffalo horn（牛角）at the koiguchi（口金）, kurigata（栗形）, and kojiri（鞘尻）. Its lacquer finish is executed in a striking dripping-gold style（滴金塗り）, complemented by a deep violet silk sageo（紫色の正絹下緒）, lending the entire mount an air of elegance and strength.

TangGu (湯谷) Kobuse Blade

This blade is hand-forged (Tezukuri / 手作り) using our own refined steel, following the principles of Japanese swordsmithing. It features a Kobuse-zukuri (甲伏造) laminated construction, reflecting the structure of traditional Tamahagane (玉钢) swords.

Blade Forging Details

• Blade Name: TangGu Traditionally Forged Kobuse Blade (甲伏造)
  

• Forging Method: This blade is forged in the Kobuse-zukuri（甲伏造） style, where a hardened outer layer of steel is forge-welded over a softer inner core. It is differentially hardened using traditional clay tempering（覆土焼入れ）, resulting in a sharp edge, resilient spine, and a visible hamon（刃文） that reflects both performance and craftsmanship.

• Materials: Steel refined in-house using traditional methods（伝統的手法による自家製鋼材）.

• Purpose: Suitable for Kenjutsu and Tameshigiri (test cutting) practice, collection, and display. Unsharpened blades are available for Iaido upon request.

Blade Specifications

• Blade Length (Nagasa刃長): Approx 73 cm
• Tang Length (Nakago 茎長): Approx. 24 cm
• Width at Base (Motohaba 元幅): Approx. 32 mm
• Thickness at Base (Motokasane 元重): Approx. 6 mm
• Width at Tip (Sakihaba 先幅): Approx. 24 mm
• Thickness at Tip (Sakikasane先重): Approx. 4 mm
• Kissaki Length (Tip 切先長): Approx. 35 mm
• Mekugi-ana (Peg Hole 目釘穴): 1

Blade Characteristics

• Shape: Shinogi-zukuri (ridged blade 鎬造), Iori-mune (flat ridged spine 庵棟), Chū-kissaki (Medium-sized tip 中切先)

• Forging Pattern (Hada 鍛肌): The forging pattern shows Masame-hada with Mokume influence（柾目肌交杢目肌）, where masame-hada（柾目肌） fine straight grain lines run longitudinally along the blade, and mokume-hada（杢目肌） swirling woodgrain-like patterns appear in layers. This is achieved through folding and directional forging in the orikaeshi-tanren（折返し鍛錬） process.
• Temper Line (Hamon 刃文): The blade has a Gunome-midare（互の目乱れ刃文） temper line, with alternating rounded peaks and valleys formed through clay tempering（覆土焼入れ / Fukutsuchi Yakiire）. Clay is applied to specific areas of the blade before quenching to control the hardness gradient and produce this pattern.

Special Features and Workmanship

Hi (Groove) Engraving

• Type: Hi-Nashi (樋なし)
• Processing Range: None (No bohi) – Solid blade for added weight and strength

Polishing Work

• TangGu Polishing Levels:
  • Highest-grade shaping polish 最上・成形研磨 
  • Superior rough polish 最上・下研ぎ 
  • Detailed final polish 最上・仕上げ研ぎ 
• Key Features:
  • The surface shows Masame-hada and Mokume-hada（柾目肌交杢目肌）, combining straight grain lines and swirling woodgrain patterns. A Gunome-midare hamon（互の目乱れ刃文） with alternating peaks and curves is formed through clay tempering（覆土焼入れ / Fukutsuchi Yakiire）. The ridge line (Hōmi 峰) is defined through traditional polishing.
    

Fittings and Mountings

Blade Fittings

• Tsuba (Handguard 鍔): Mokko-style Tsuba (木瓜鍔) – Blackened Iron (鉄地), featuring a classic four-lobed silhouette with an openwork axe motif. A practical and symbolic guard rooted in tradition.
• Fuchi-Kashira (縁頭): Smooth polished fuchi-kashira made from solid copper, with no engravings — minimalist and practical.
• Menuki (目貫): Matched arrowhead-style menuki, cast in matte white copper.
• Habaki (鎺): Crafted from red copper (akagane / 赤銅) with a smooth – finish.
• Samegawa (Ray Skin 柄鮫): Premium natural ray skin
• Handle Wrapping (Tsuka-maki 柄巻): High-quality green silk ito, tightly wrapped with hishigami (paper triangles) for a symmetrical and secure grip.

Saya and Accessories

• Saya (Scabbard 鞘): The saya is made in uchigatana koshirae style（打刀拵）with buffalo horn fittings（牛角 / Gyu-kaku）at the koiguchi（口金）, kurigata（栗形）, and kojiri（鞘尻）.
• Saya Lacquer (鞘塗): Finished with dripping gold-style lacquer（滴金塗り）.
• Sageo (Cord 下緒): Deep violet silk sageo for an elegant and secure presentation.

Measurements

• Blade Weight: Approx. 0.6 kg
• Sword Weight (without Saya): Approx. 0.95 kg
• Total Weight: Approx. 1.2 kg
• Overall Length: Approx. 102 mm