- T4000 S Black Forprene, Satin is a continuation of Extrema Ratio's collection of tanto knives. For those who love the Japanese Blade profile, but don't want to give up the tactical Handle. Incredibly fast, perfectly balanced. A tool for the professional

This product is intended for use only by adults with knowledge and experience in handling sharp cutting tools. Improper use of the knife can result in serious injuries. The blade is extremely sharp and can easily cut through skin and tissue; therefore, extra caution should always be exercised while cutting, and hands should be kept away from the cutting edge. To prevent the knife from slipping, it is recommended to cut on a stable, non-slip surface and avoid excessive force, which may cause uncontrolled blade movement.
Leaving the knife on the edge of a table, countertop, or in easily accessible places—especially where children are present—poses a significant safety risk. The knife should always be properly secured after use, ideally by placing it on a stable surface or storing it in designated knife blocks, protective sheaths, or magnetic strips. The knife should never be used for tasks it is not designed for, such as opening cans or prying objects, as this can damage the tool and lead to dangerous accidents.
A dull blade increases the risk of injury, as it requires more force and is more likely to slip from the material being cut. Therefore, it is essential to sharpen the knife regularly to maintain optimal sharpness. Additionally, proper cleaning and drying of the knife are necessary to prevent corrosion and bacterial growth. Periodic inspection of the handle and blade is recommended to check for cracks, chips, or looseness. If any damage is detected, the knife should be repaired or replaced immediately.
When using the knife, focus solely on the task at hand—avoid talking on the phone, watching television, or other distractions while cutting. Ensure proper lighting in the workspace for better visibility and control. Please note that some countries or regions have laws restricting the ownership and carrying of knives. Before purchasing or using this knife, verify that its use is legal in your location according to applicable regulations.
Following these safety guidelines will help ensure safe and effective knife use, minimizing the risk of accidents and extending the lifespan of the tool.
T4000 S Black Forprene, Satin is a continuation of Extrema Ratio's collection of knives with a tanto blade. A choice for those who love knives with a Japanese Blade shape, yet do not want to give up the tactical Handle and tactical Sheath. Perfectly balanced “on the Blade” with above-average durability. Full-size knife with full tang construction for use on the battlefield likes every day. In skilled hands incredibly fast and dangerous. A typical tool of a professional.
N690 - corrosion-resistant, high-carbon 1.07% (C), martensitic chromium steel 17.30% (Cr) with molybdenum 1.10% (Mo), vanadium 0.10% (V) and cobalt 1.50% (Co) for structural uniformity. Features exceptionally high corrosion resistance and long edge retention. One of the best tool steels in the world today. Achieves a hardness of 58 HRC. Manufactured by Böhler Edelstahl in Kapfenberg, Austria.
Blade - radically durable Tanto with a thickness of 4 mm. On both sides of the blade grain / drainage grooves (blood-draining slots). The blade is finished with an elegant satin finish. Plain blade was derived with a high flat grind (Flat grind ), which maintains high sharpness of the cutting edge and penetration ability regardless of the intensity of wear.
Handle - full-size from 5 “ length type ‘FH ’ (Full Handle) used in assault knives. Textured, non-slip grips with rubber-like properties, made of Forprene thermoplastic elastomer (flexible return, softness, chemical resistance), provide a secure grip even with wet hands. Pommel steel head with an oval hole (lanyard hole) for pulling a lanyard or safety line, can act as a hammer / glass breaker and more.
Sheath - tacticalsheath made of abrasion-resistant, waterproof Cordura in black. The snap-fastened case protects the knife well from falling out. Compatible with the M.O.L.L.E. standard allows the holster to be attached to the belt or under the straps of the MOLLE system (Modular Lightweight Load-carrying Equipment).
Technical data:
Product number: 04.1000.0436/SAT
Name: T4000 S Black Forprene, Satin
Overall length: 304.0 mm / 12.0”
Blade length: 174.0 mm / 6.9”
Blade thickness: 4.0 mm / 0.16”
Handle length: n.d.
Handle thickness: n.d.
Weight: 264.0 g / 9.3 oz
Blade material: Böhler N690
Blade hardness: 58 HRC
Blade grind: Flat
Blade finish: Satin
Handle material: Forprene
Handle finish color: Black
Sheath: Cordura Black
Additional accessories: None
Designer: Extrema Ratio
Brand: Extrema Ratio
Manufacturer: Extrema Ratio, Italy
Country of Origin: Italy
Developed by: the Sharg® company