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ExtremaRatio - Ti-Rock Satin SanMai CoS - Titanium Grey - Limited Edition - PRIVATE COLLECTION - knife

Venduto / Sold

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Knife with serial number 18/33 - withdrawn from private collection - with original box and certificates - in near new condition - factory sharpening slightly worn, perhaps due to some cutting test made by the previous owner; otherwise absolutely free of imperfections or wear. Checked and certified by our internal laboratory. 


Exclusive Coltelleria Collini - Available in only 33 numbered pieces on blade and box

New version of the Ti-Rock presented in December 2015. This new 2016 edition features a satin finish blade in Japanese rolled steel produced by Takefu Steel. Specifically, CoS at 61.5 HRC (Cobalt Special considered mechanically 25% higher than the already appreciated VG10) is used for the central plate and 420J2 (at 56 HRC) for the two side plates, in order to have a very high cutting capacity but at the same time a remarkable resilience and resistance to oxidation. This new version is produced in three different colors of titanium; Blue, Gray and Black and is limited to a run of only 33 pieces per color.

Intended use: collection / EDC / CQD

Production type: industrial, limited
Blade: Japanese rolled stainless steel (San Mai) with CoS cutting edge at 61.5HRC cryogenically hardened; with double concave shank in the strong part of the blade
Blade treatment: Satin finish
Country of production: Italy
Handle: Titanium, machined from solid, with integral Frame Lock closure system with removable hinge and safety made of stainless steel
Blade length: 75mm.
Blade thickness: 6.3mm.
Total lenght: 180mm.
Weight: 186g.
Clip: stainless steel, reversible, deep pocket type and with tip up port.
Notes: Conical Skull Crasher inserted in the tang - Limited edition with only 33 numbered pieces serialized on the blade and box.
Box: cardboard box, numbered, with ExtremaRatio and Coltelleria Collini logos

As in the ancient swords of the Japanese Samurai.

The rolled steel - imported in Italy by Collini Steel directly from the Japanese Takefu Steel - is based on the ancient Japanese tradition in the creation of the famous Samurai swords. As early as 1100, expert Japanese blacksmiths combined different materials to give Katana swords incredible cutting capabilities combined with previously unknown strength and flexibility. It is thanks to this revolutionary construction technique that the Samurai swords have been preserved until our days becoming one of the most fascinating objects made by man. Following this tradition applied to modern metallurgy, we are now able to have technologically advanced steels already tested and used in cutlery also by famous brands such as Fallkniven, Cold Steel, Mcusta, Kai, Sog, Zwilling, Rockstead, etc.

Features of San Mai steel: It is made of different types of metals alloyed together to create a composite that contains and intensifies the strengths of the metals taken individually:

- Longer cutting edge life
thanks to the use of high quality steels with a high carbon content (VG10, CoS, Shiro) or sintered (SPG2), in the core steel, the blade, once hardened, reaches hardness and cutting performance decidedly superior to those achieved with the use of traditional steels.

- Greater resilience
Built on the principle of Japanese swords, the multilayer steel is difficult to break thanks to the toughness of the central steel (Core Steel) and the elasticity of the steel used for the lateral coating (Stainless Steel).

- Improved corrosion resistance
The steel used for the outer layers (Stainless Steel) gives the blade a high resistance to corrosion. The combination of the two or more materials used by Takefu Steel generates, at a galvanic level, a structure that improves corrosion resistance even on the edge.

- Easy machining even after heat treatment
Although steel normally becomes harder after hardening, the lateral steel used in multilayer machining does not lose its softness and allows easy machining, drilling or welding even after heat treatment. For optimum blade performance, cryogenic treatment is recommended.

- Improved aesthetic performance
Knives made of multi-state steel or damascus pattern at the end of the processing are aesthetically elegant, refined and highly appreciated by collectors all over the world.



Articolo dedicato al Ti-Rock sul numero 75 di Coltelli (click sull'immagine per visualizzare il pdf)


Extrema Ratio Ti-Rock



More Information
Country of productionItaly
Blade TypeFolding
Blade Length7/8cm
Blade TipDrop point
Blade thickness6,5 mm
Stainless SteelCoS (laminated)
Handle MaterialTitanium
Locking TypeFrame Lock
RarityLimited Edition, Very Rare
Materials and Finishes8
Steel Quality8,5
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