Katana Vermilion Bloom Maru Blade Beni-Zakura Koshirae 花綻

Clay Tempered Full Tang Shinken (真剣) | Vermilion Bloom Katana: TangGu (湯谷) Maru Blade (丸造) + TangGu (湯谷) Beni-Zakura Koshirae (紅桜拵)

This katana is hand-forged (Tezukuri / 手作り) from high-carbon modern steel (高炭素現代鋼) in the Maru-zukuri (丸造) style. The blade is clay-tempered (yaki-ire / 焼入れ) to produce a straight suguha hamon (直刃刃文). The koshirae includes a mokko-gata tsuba (木瓜形鍔) made of tetsu (鉄地, iron) with a blackened finish (yaki-sabi / 煮黒). The fuchi-kashira (縁頭) are made of hakudo (白銅) with engraved sakura motifs. The habaki (鎺) is made of shakudo (赤銅), and the menuki (目貫) are made of hakudo (白銅) with floral engravings. The tsuka is wrapped in red synthetic fiber ito (赤色合成柄糸) over natural samegawa (鮫皮) with hishigami (菱紙) forming a diamond pattern (hishi-gumi / 菱組). The saya is finished in red ishime-nuri (赤石目塗) lacquer with buffalo horn (gyūkaku / 牛角) koiguchi, kurigata, and kojiri. The sageo (下緒) is red synthetic fiber (赤色合成下緒), tightly woven.

TangGu (湯谷) Maru Blade

This blade is hand-forged (Tezukuri / 手作り) from high-carbon modern steel (高炭素現代鋼) in a monosteel construction called Maru-zukuri (丸造).

Blade Forging Details

• Blade Name: TangGu Traditionally Forged Maru Blade (丸造)
• Forging Method: This blade is forged in the Maru-zukuri (丸造) style from a single piece of modern high-carbon steel. It is clay-tempered (yaki-ire / 焼入れ) to produce a hardened edge with a visible hamon (刃文).

• Materials: Modern high-carbon steel (kōtanso gendai-kō / 高炭素現代鋼)
• Purpose: Designed for Iaido (non-sharpened), Kenjutsu, and Tameshigiri (test cutting) practice

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): None (Modern monosteel; no visible hada)
• Hamono (Blade Pattern 刃文): Clay-tempered suguha-style (直刃) hamon – The blade is differentially hardened (yaki-ire / 焼入れ) to produce a functional temper line.

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:
  • High-grade shaping polish 上・成形研磨
  • High-grade rough polish 上・下研ぎ
  • High-grade final polish 上・仕上げ研磨
    
• Key Features:
  • Refined blade geometry and balanced weight distribution
  • Exceptional sharpness and durability with a clean, bright-polished edge (Hashiro)
    

Fittings and Mountings

Blade Fittings

• Tsuba (Handguard 鍔): Mokko-gata Tsuba (木瓜形鍔) – Forged from tetsu (鉄地, iron) with a blackened surface (yaki-sabi / 煮黒).
• Fuchi-Kashira (縁頭): Made from hakudo (白銅, white copper), blackened and engraved with sakura (cherry blossom) motifs.
• Menuki (目貫): Made from hakudo (白銅), blackened and engraved with floral motifs.
• Habaki (鎺): Shakudo Habaki (赤銅鎺) – Made from reddish copper alloy (shakudo / 赤銅) with a polished surface.
• Samegawa (Ray Skin 柄鮫): Natural rayskin (samegawa / 鮫皮) beneath the tsuka-maki.
• Handle Wrapping (Tsuka-maki 柄巻): Red cotton ito wrapped over hishigami (菱紙) in a diamond pattern (hishi-gumi / 菱組).

Saya and Accessories

• Saya (Scabbard 鞘): Traditional-style saya (拵風鞘), reinforced with water buffalo horn (牛角) at the koiguchi (鞘口), kojiri (鐺), and kurigata (栗形) for added durability.

• Saya Lacquer (鞘塗): Red ishime-nuri (赤石目塗) with a textured matte finish.

• Sageo (Cord 下緒): Red synthetic fiber sageo (赤色合成下緒), tightly woven.

Measurements

• Blade Weight: Approx. 0.65 kg
• Sword Weight (without Saya): Approx. 1.0 kg
• Total Weight: Approx. 1.3 kg
• Overall Length: Approx. 102 mm