Katana Tiger Tamer Sanmai Blade Koko Koshirae 黑曜

Clay Tempered Full Tang Shinken (真剣) | Tiger Tamer Katana: TangGu (湯谷) Sanmai Blade (三枚造) + TangGu (湯谷) Koko Koshirae (降虎拵)

This katana is forged in sanmai (三枚) construction with a hardened steel core and softer outer layers, achieving a balance of sharpness and durability. The blade shows masame-hada (柾目肌) grain and a suguha hamon with traces of komidare (小乱れ交じり直刃), created by traditional clay tempering (覆土焼入れ). Made in the shinogi-zukuri (鎬造) style with an iori-mune (庵棟) spine and an ō-kissaki (大切先), the blade weighs about 500 grams and offers good agility and balance. The tsuba (鍔) has a "tiger descending the mountain" (虎下山) motif in patinated copper (煮黒). The fuchi, kashira, and menuki (目貫) match in material and finish. The tsuka (柄) is wrapped in black cotton ito (綿糸) over aged white samegawa (鮫皮) with hishigami (菱紙) for a secure grip. The saya (鞘) is made of lacquered hardwood with buffalo horn reinforcements on the koiguchi, kojiri, and kurigata. A black cotton sageo (下緒) is tied for use.

TangGu (湯谷) Sanmai Blade

This blade is hand-forged (Tezukuri / 手作り) using our own refined steel in Sanmai-zukuri（三枚造）construction, with a hard edge forge-welded between two softer outer layers.

Blade Forging Details

• Blade Name: TangGu Traditionally Forged Sanmai Blade (三枚造)
• Forging Method: This blade is forged in the Sanmai-zukuri（三枚造）style, with a hard steel core forge-welded between two layers of softer outer steel. It is differentially hardened using clay tempering（覆土焼入れ）, producing a hardened edge and a softer spine. This process also creates a visible hamon（刃文）.
• Materials: Steel refined in-house using traditional methods（伝統的手法による自家製鋼材）
• Purpose: Designed for Iaido (non-sharpened), Kenjutsu, and Tameshigiri (test cutting) practice, as well as for collection, display, and appreciation by enthusiasts and connoisseurs.

Blade Specifications

• Blade Length (Nagasa刃長): Approx 73 cm
• Tang Length (Nakago 茎長): Approx. 25 cm
• Width at Base (Motohaba 元幅): Approx. 30 mm
• Thickness at Base (Motokasane 元重): Approx. 5.5 mm
• Width at Tip (Sakihaba 先幅): Approx. 22 mm
• Thickness at Tip (Sakikasane先重): Approx. 3.5 mm
• Kissaki Length (Tip 切先長): Approx. 40 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), Ō-kissaki (Large-sized tip 大切先)

• Forging Pattern (Hada 鍛肌): Masame-hada（柾目肌）— straight-grained forging pattern made through layered forging in sanmai-zukuri（三枚造）style.
• Hamono (Blade Pattern 刃文): Suguha-style hamon with traces of komidare（小乱れ交じり直刃）, created by clay tempering（覆土焼入れ）.

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 blade has a core-hard edge in sanmai（三枚）construction,and weight is approximately 500 grams. Hand polishing shows the bright edge (刃白, hakuba), matte ji surface (柾目肌 jihada), and mirror-polished shinogi line (鋒身筋, hōmi).

Fittings and Mountings

Blade Fittings

• Tsuba (Handguard 鍔): Maru-gata (丸形) handguard forged from solid copper (銅 dō) with a black patina (煮黒 nuriguro). Features a "tiger descending the mountain" (虎下山) motif in relief.
• Fuchi-Kashira (縁頭): Made from black-patinated copper, matching the tsuba in design and finish.
• Menuki (目貫): Abstract forms positioned beneath the tsuka-ito for grip support.
• Habaki (鎺): Polished copper habaki with a plain surface, connecting blade and mountings.
• Samegawa (Ray Skin 柄鮫): Genuine ray skin (鮫皮) with an aged finish.
• Handle Wrapping (Tsuka-maki 柄巻): Black cotton ito (黒色綿糸) wrapped in hishigami (菱紙) style with angular folds.

Saya and Accessories

• Saya (Scabbard 鞘): Traditional-style saya (拵風鞘), reinforced with water buffalo horn at the koiguchi (mouth), kojiri (end), and kurigata (cord knob).
• Saya Lacquer (鞘塗): Deep black lacquer with subtle sparkling highlights.
• Sageo (Cord 下緒): Black cotton sageo, tied securely.

Measurements

• Blade Weight: Approx. 0.5 kg
• Sword Weight (without Saya): Approx. 0.80 kg
• Total Weight: Approx. 1.0 kg
• Overall Length: Approx. 102 mm