Katana Tide Breaker Sanmai Blade Shioban Koshirae 破潮

Clay Tempered Full Tang Shinken (真剣) | Tide Breaker Katana: TangGu (湯谷) Sanmai Blade (三枚造) + TangGu (湯谷) Shioban Koshirae (潮波拵)

This katana, named Tidebreaker, is mounted in Shioban Koshirae（潮波拵）. The blade is forged in Sanmai（三枚構造） construction, placing a hardened steel core between softer outer layers for strength, durability, and balanced cutting performance. It is clay tempered（覆土焼入れ）, forming a flowing Notare-style hamon（のたれ刃文） along the edge. The surface shows Masame-hada mixed with Itame-hada（柾目肌交板目肌）, combining straight and wood-grain patterns that reflect refined folding workmanship. The saya（鞘） is finished in Kin Mushikui lacquer（金虫喰塗）, featuring a distinctive gold-speckled texture that shimmers subtly under changing light. The koiguchi（鞘口）, kurigata（栗形）, and kojiri（鐺） are reinforced with water buffalo horn（牛角）. The tsuka（柄） is wrapped in brown ito（茶色柄糸） over black samegawa（黒鮫皮）, with hishigami（菱紙） inserted to create crisp and uniform diamond patterns. The fuchi-kashira（縁頭） are blackened brass（煮黒真鍮） crafted in nanako-ji texture（魚子地） and engraved with traditional family crest motifs（家紋彫り / Kamon-bori）. The tsuba（鍔） is a mokko-gata brass guard（木瓜形真鍮鍔） engraved with flowing wave motifs（波紋図）, symbolizing the sea, movement, and harmonious strength. The habaki（鎺） is polished brass（真鍮） with a smooth finish, completing the elegant maritime-themed mounting.

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: 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 71 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 blade shows masame-hada（柾目肌）with long, straight grain lines. Variations in the grain include itame-hada（板目肌）and transitional textures, created through layered forging in the sanmai-zukuri（三枚構造）style.
• Temper Line (Hamon 刃文): A Notare-style hamon（のたれ刃文）runs along the cutting edge, formed through clay tempering（覆土焼入れ / Fukutsuchi Yakiire）.

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 

Fittings and Mountings

Blade Fittings

• Tsuba (Handguard 鍔): A Mokko-gata (木瓜形) tsuba crafted from brass（真鍮 / Shinchū）, engraved with elegant wave motifs（波紋図).
• Fuchi-Kashira (縁頭): Blackened brass（煮黒真鍮 / Shinchū）fuchi-kashira crafted in the refined nanako-ji style（魚子地）, intricately engraved with family crest motifs（家紋彫り / Kamon-bori）
• Menuki (目貫): Blackened white-copper wave-themed menuki（海浪図）
• Habaki (鎺): Polished brass（真鍮 / Shinchū）habaki with a smooth surface
• Samegawa (Ray Skin 柄鮫): Genuine black samegawa（黒鮫皮）laid beneath the handle wrap
• Handle Wrapping (柄巻): Brown cotton (or rayon) tsuka-ito wrapped using hishigami（菱紙）to form diamond patterns.

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): Finished in Kin Mushikui lacquer（金虫喰塗）, featuring a distinctive gold-speckled texture.
• Sageo (Cord 下緒): Japanese-made sageo available in multiple colors

Measurements

• Blade Weight: Approx. 0.65 kg
• Sword Weight (without Saya): Approx. 1.00 kg
• Total Weight: Approx. 1.25 kg
• Overall Length: Approx. 102 mm