Extrema Ratio

Extrema Ratio is an Italian brand of tactical knives, founded in 1997. The company develops knives for military, police, rescue services, and outdoor use. Extrema Ratio officially supplies knives to the Italian armed forces and security forces, and is ISO 9001 certified and has a NATO supplier code.

You can buy original Extrema Ratio knives at MyGoodKnife—our store is the brand's official dealer. Our selection includes folding tactical knives and fixed-blade knives from popular Extrema Ratio series: Col Moschin, Fulcrum, RAO, Caimano Nero, Dobermann, Selvans, Misericordia, S-THIL, and others.

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New
Fixed blade Knife Extrema Ratio Aero Nitrogen FX Green Orange 8cm 0410000182NITBLKC8A1
The Extrema Ratio Aero Nitrogen FX is a new fixed-blade knife designed for everyday and outdoor use. The 80mm blade is made of nitrided steel and features a black coating for increased resistance to external influences and reduced glare. The handle is made of corrosion-resistant Forest Green aluminum and features orange screws. Interchangeable AERO scales allow you to customize the color scheme or combine different scale options. The Extrema Ratio Aero Nitrogen FX weighs 117g.
€187.25

In stock

New
Folding knife Extrema Ratio Aero Nitrogen Black Orange 6.9cm 0410000180NITBLKA1
The Extrema Ratio Aero Nitrogen is a compact folding knife with a nitrided steel blade. This alloy is highly resistant to corrosion and wear. The knife requires minimal maintenance and is well-suited for EDC use. The handle is made of corrosion-resistant aluminum and features black and orange scales for a secure and comfortable grip. A distinctive feature of the AERO series is the replaceable scales. They can be replaced in just a few simple steps. The Extrema Ratio Aero Nitrogen blade is 69 mm long and weighs approximately 92 g. Its striking, modern design and excellent functionality immediately made the Extrema Ratio Aero popular worldwide.
€179.28

In stock

New
Folding knife Extrema Ratio Satre F Total Black 7cm 0410000246BLKA1
The Extrema Ratio SATRE F is a compact folding knife designed for everyday carry (EDC). The flipper allows for instant and intuitive blade deployment. The design utilizes a double steel liner, providing remarkable rigidity while remaining ultra-lightweight. It features a liner-lock. The handle scales are made of durable and grippy aluminum. The black blade is made of premium N690 steel. A "Deep Carry" wire clip allows for convenient storage in a pocket or on a rig. The Extrema Ratio SATRE F weighs only 78g. Its overall length is 174mm, and its blade length is 70mm.
€168.92

In stock

Fixed blade Knife Extrema Ratio Satre Black 6.8cm 0410000222BLK
 The Extrema Ratio Satre Black is a pocket-sized, light and extremely resistant fixed blade knife. Given its characteristics, it can be employed in a large variety of activities and fields, including survival and bushcraft, or it can be part of an EDC. It was designed in collaboration with Daniele Dal Canto, a Master Advanced F.I.S.S.S. instructor (Italian Federation of Sport and Experimental Survival). It can be worn as a neck knife thanks to its Paracord 550 lanyard.  The pre-shaped Kydex sheath has eyelets, allowing to apply both lanyard and accessory holder. This allows to clip the sheath together with not only belts, but also pockets, trousers, jackets, shirts and t-shirts. ULTICLIP gives the possibility to position the knife both vertically and horizontally and allows a more accessible use for left and right handed. The full-tang skeletonized structure allows the customization of the knife by using the Paracord as an handle cover. Satre is made with heat-treated Böhler N690 steel at 58 HRC. This material was chosen for its resistance to oxidation, for the durability of its edge and especially for its reliability, which has been proven over the years. 
€129.88

In stock

Fixed blade Knife Extrema Ratio Col Moschin Desert Warfare 15cm 04.1000.0125/DW
Commissioned and officially adopted in 2002 by the Ninth Rgt. Incursori "Col. Moschin", this model is the quintessence of a pure combat knife. Inspired by daggers with an asymmetric blade and straight but slightly orientated handle used by the Arditi, in whose footsteps the Col Moschin Regiment follows, it has been re-elaborated in a modern form, endowed with a double edged blade, (single for the civilian version), integral guards and a removable E.R.M.H. handle in Forprene. Both grindings are hollow grind razor sharp. The centre of gravity is towards the end of the handle, the point especially sharp, it is light, manageable and intuitive. Each new Incursore receives one, and each new Incursore is trained to use it in the best way.
€343.43

In stock

Fixed blade Knife Extrema Ratio Contact Desert 16.2cm 04.1000.0215/DW
Extrema Ratio Contact Desert version. Contact is a first knife of Extrema Ratio new production line. It has a blade with a lance-shaped profile, a flat grinding and a diamond-shaped geometry. Contact has got a lower guard branch to protect the hand from accidental cuts, upper jumping to improve grip, a concave fuller along the entire length of the blade and a generous thickness blade (6.30mm) All these details make the Contact the elder brother of the now famous Requiem, revisited in proportions and in some technical features. The blade is made in Böhler N690 steel with a hardness of 58 HRC. The sheath is minimalist; most of the fabric has been cut off; it has got a 2nd level retention system, remembering the style of the model it was inspired by.
€241.43

In stock

Folding knife Extrema Ratio Caimano Nero 9.3cm 0410000169BLK
The Caimano Nero is a tactical knife delivered to the G.O.I., Gruppo Operativo Incursori (Operational Raiders Group) of the Italian Navy, and designed by Extrema Ratio, official COMSUBIN supplier. Its name is a reference and a tribute to the heroic Caimani Neri del Piave (Black Caimans of the Piave river), a unit of the Arditi della Regia Marina (Italian Royal Navy), who used to swim across the Piave river to carry out raids on enemy territory during the First World War. It is an automatic knife with a 4 mm asymmetrical spearpoint blade and a partial sharp false edge to improve the coefficient of penetration. The serrated part of the edge allow to cut highly-resistent cables and fabrics without losing its sharpening. It is a medium folder with a robust structure. It is light and balanced thanks to numerous removal processes applied to its highly-thick aluminum handle scales. The pommel, which recalls the shape of the tail/propel section of the Siluro a lenta corsa (S.L.C.), is designed to improve a rapid extraction of the knife from the pocket. The DLC-coated titanium clip can be positioned in three different angles on both sides to allow maximum customization while wearing it. Its shape is designed to conceal the handle sticking out of the pocket. The automatic blade release system guarantees a complete opening even in the event of accidental impacts during the opening rotation. Among its features, it is equipped with an hard-metal glass breaker and a lock, which prevents the blade from dangerously closing by accident.
€346.61

In stock

New
Fixed blade Knife Extrema Ratio A.S.F.K. 16.2cm 04.1000.0438/BLK
A.S.F.K. is a dagger dedicated to and adopted by the new Comando Forze Speciali Esercito Italiano (Italian Special Forces). A.S.F.K. revives the Arditi tradition and cold weapon assaults which are characteristic of trench warfare. A.S.F.K. is a contemporary interpretation of the famous trench knife. It comes with N690 Böhler steel blade, forprene handle and a ring guard for hand protection while using it as a glass breaker.
€338.65

In stock

Extrema Ratio Versa Satin 8cm 0410000214SAT
Versa is a new multipurpose knife from Extrema Ratio. This models has a monolithic construction made of Bohler N690 steel. 80 mm blade has a tanto profile. Name Versa, perfectly embodies the characteristics of this knife; its versatility makes it suitable for a variety of situations. Extrema Ratio Versa good as Every Day Carry knife, and as outdoor, survival, bushcraft or hunting knife. Satin version is convinient as EDC knife. Weight is 110 g. Versa comes with kydex sheath.
€135.46

In stock

Folding knife Extrema Ratio Ant Urban Neon SF Yellow Black 5.1cm 041000471BLKYL
The Extrema Ratio Ant Urban Neon is a folding knife that breaks the monotony of the city. Live in color where others live in gray. The vibrant yellow handle is crafted from anodized aluminum. The black steel blade has a DLC (diamond-like carbon) coating. The Extrema Ratio Ant Urban Neon features a clip and lanyard hole. It also features a frame lock.
€107.57

In stock

Folding knife Extrema Ratio Ant Urban SF Black Satin 5.1cm 041000471SATBLK
The Extrema Ratio Ant Urban SF knife features a black aluminum handle. This lightweight folding knife weighs just 44 grams and is ideal for everyday use. Its clip makes it easy to carry in your pocket, and the lanyard hole allows for a lanyard. The 5 cm long sheepskin blade is crafted from Bohler N690 steel and has a satin finish.
€95.62

In stock

Folding knife Extrema Ratio Ant Urban SF Cherry Satin 5.1cm 041000471SATBCY
The compact Extrema Ratio Ant Urban EDC knife is designed for urban use. Its sheepskin blade, just 5 cm long, is perfect for everyday tasks. The blade is crafted from Bohler N690 steel. The handle is cherry-colored aluminum. For easy carrying, the Extrema Ratio Ant Urban features a lanyard hole and a pocket clip. It weighs 44 g.
€101.99

In stock

Diving knife Extrema Ratio Dicok 8.1cm 04.1000.0318/BLK
DICOK - Diving Compact Knife This diving knife has been designed together with experts in diving sector. It has got a suitable size to be easily used in water environment. This is to offer a working tool and an essential part of underwater equipment. The blade is made out of stainless steel with chemical burnishing process which makes it highly resistant to corrosion.It is highly resistant to keep the sharpening edge and to flexing. It is planned to be used as a lever thanks to its cut tip, and to cut nets, ropes and fabrics thanks to the serration on the blade.Nylon fabrics and polyester tapes together with a anti-slip rubber membrane form the soft part of the sheath. The hard part is in Kydex.The sheath is designed to allow multiple mounting both to the equipment and to the body of the user. The handle is in nylon loaded with glass fibers and it presents an anti-slip finishing which makes the handle ergonomic and perfectly fitting both the glove and the bare hand of user. This enables both precision and strength works. On the sheath an anti-panic opening system has been planned which enables a quick release of the knife by simply pulling, avoiding to act on the retaining buckle.
€207.17

In stock

Fixed blade Knife Extrema Ratio RAO Steel N690 Dark Stone 8.7cm 0410000221BLKSW
The Extrema Ratio RAO STEEL is a robust, compact outdoor knife. It's ideal for hiking, camping, survival, and other outdoor activities. Its 5mm fixed blade is ready for any challenge. The design is based on the renowned RAO folding knife. As a fixed blade knife, the Extrema Ratio RAO STEEL is designed for active use in the field, in the wilderness, and for any outdoor task. It's made of Böhler N690 steel (58 HRC) with MIL-C-13924 treatment and a stonewashed finish. The knife features a lanyard hole and a caides sheath with a belt clip.
€171.31

In stock

Folding knife Extrema Ratio RAO Black 11.9cm 04.1000.0141/BLK
In June 2006, the “185° Rgt. Ricognizione e Acquisizione Obiettivi” (Target Acquisition Regiment) airborne “FOLGORE” (185° RAO) entrusted to Extrema Ratio the development of a unique knife fitting the unit’s specific operational duties. This resulted in the RAO: not an oversized folder as much as a compact survival & field knife, with a heavy and dependable blade. Its very reliable locking system, assisted by an extra safety device, effectively turns this folder into a fixed blade knife. The opening and closing is to be performed with both hands in order to minimize the risk of self-inflicted injuries, as the blade, because of its weight, is a veritable guillotine. The extra safe device is a steel pin to be hand-screwed through two holes by the guard section of the massive Anticorodal aluminum handle – its presence between blade and hand also acting as a great psychological boon. The sheath is an essential part of this weapon system: it holds a diamond-plate sharpener and enables user to carry the knife either in open position, held in place by a cord and two clips, or closed, inside the front pocket. The sheath can be attached to tactical vests or common belts, being MOLLE system-compliant.
€334.68

In stock

Fixed blade Knife Extrema Ratio Venatus F Black Satin 11.9cm 0410000089SATBLK
VENATUS F Black satin is a new hunting knife from the Italian manufacturer Extrema Ratio. This is the first hunting series created for those who perceive hunting not as entertainment, but as an ancient language of observation, patience and respect. This version of the VENATUS knife is equipped with a blade made of Böhler N690 steel. Satin finish of the blade. Comfortable, ergonomic handle with G10 overlays. Each VENATUS knife comes with a leather sheath made with the same care as the blade itself. But it is not only about aesthetics: it is a technical element designed to adapt to the body and movements of the hunter. This is the first symmetrical modular leather sheath, allowing for different carrying options: vertical attachment to the belt or thigh, or horizontal carrying using the detachable back strap.
€203.19

Shipping after 10-20 business days

Folding knife Extrema Ratio LKU01 Urban Sideral 10cm
Extrema Ratio LKU01 URBAN Sideral is a new Italian EDC folding knife suitable also for tactical tasks. Knife has the 10 cm blade made of Böhler N690 steel blade. Handle scales are made of anticorodal aluminium. The pocket clip, made of stainless steel, is removable and reversible to ensure ambidextrous use. Extrema Ratio LKU01 URBAN Sideral weights 123 g. 
€182.47

In stock

Folding knife Extrema Ratio Ant Black Stone Washed 5cm 041000467SWBLK
Extrema Ratio Ant is a small Every Day Carry folding knife. It has just 5 cm blade made of Bohler N690 steel. This version of Extrema Ratio Ant has black handle scales and Stone Washed blade. Knife has a pocket clip for ease of carrying. The sheepsfoot blade of Ant pocket knife is equipped with a small slot on the top to facilitate opening.
€97.21

In stock

Folding knife Extrema Ratio LKU01 Urban Dark 10cm
Extrema Ratio LKU01 URBAN Dark is a folding knife that combines Italian elegance and combat strategy. It has the 58 HRC hardened Böhler N690 steel blade and the anticorodal aluminium handle scales. The clip, made of stainless steel, is removable and reversible to ensure ambidextrous use. Extrema Ratio LKU01 URBAN Dark weights 123 g. 
€182.47

In stock

Fixed blade Knife Extrema Ratio Herring NE 16.7cm 04.1000.0319/BL-OR-N
Extrema Ratio Herring is one of the fan favorite military daggers. The dagger that entered the history of Italy during the World War II, thanks to the deeds of the young soldiers of the 1st Reconnaissance Squadron Folgore, armed with this weapon during Operation Herring. Extrema Ratio wanted to pay homage to this dagger while retaining the original design using most modern production techniques. The unique handcrafted finish on the handle mimics the aging of brass and gives the dagger a vintage look. The Herring NE version has an unsharpened cutting edge, which allows you to safely store this dagger.
€463.71

In stock

Fixed blade Knife Extrema Ratio Vipera total black M390 11.6cm 0410000484M3BLKBLK
Requiem's tactical advantage and Mamba's emphasis on survival were combined to create VIPERA, which weighs less than 100g (3.5 oz) and offers speed, toughness, and precision. Its long drop-point blade, which has a full-flat, narrow-edge grind for razor-like cuts, pierces easily. Heat-treated to 61 HRC, it strikes a balance between durability and sharpness. Two high-performance steels with superior corrosion resistance and edge retention are available. Even under harsh circumstances, the handle's incorporated bottom guard ensures a firm grip. Vipera is lightweight, discrete, and designed for agility and control. The nylon ASPIS sheath is perfect for EDC in tactical, urban, survival, off-road, and outdoor settings; it mounts readily to belts, packs, and M.O.L.L.E systems. Vipera, designed for real-world missions, combines a small size with unwavering performance.
€179.28

In stock

Folding knife Extrema Ratio T911 Rescue 7.6cm 0410000164SW-RED
The T911 RESCUE is an updated version of the T911 folding knife, designed for quick and effective response in emergency situations. The knife is equipped with a bright visible red aluminum handle. The blade of the modified Spear Point profile has a serrated base. This allows you to quickly cut ropes and other durable materials. The blade is made of heat-treated Böhler N690 steel with a Stone Washed coating. The T911 RESCUE is a true multi-functional tool designed for emergency situations. The handle includes a rope cutter with an easily accessible and replaceable blade, a glass breaker, spike and a screw driver.
€298.80

In stock

New
Folding knife Extrema Ratio MF1 Evo SP Black M390 9.5cm
Extrema Ratio MF1 EVO SP is equipped with a Spear Point blade made of Böhler M390 steel. The handle is made of anodized aluminum, resistant to all weather conditions and rust. The blade locking mechanism Liner lock is additionally supported by the new generation safety system "HIDDEN LOCK". The weight of Extrema ratio MF1 Evo SP Black M390 is 185 g.
€267.73

In stock

Folding knife Extrema Ratio MF1 Evo D Tactical Grey 9.5cm 04.1000.0232/BLK/GRY
Extrema Ratio MF1 Evo D Tactical Grey is equipped with a blade made of Bohler N690 steel. The blade length is 95 mm. The Tactical Grey handle consists of two finely processed anodized aluminum plates. A double-sided steel clip allows you to hide the knife in your pocket. The Extrema Ratio MF1 Evo D blade locking mechanism is LINER-LOCK, supported by the new generation security system "HIDDEN LOCK".
€221.51

In stock

Extrema Ratio knives are part of the equipment of many special military units in Italy, as well as police and rescue services. Each model is developed very carefully and undergoes a series of strict tests before being launched into production. The company collaborates with the University of Perugia, where scientists conduct a number of studies, determining the ergonomics of Extrema Ratio products and methods for their improvement. Both Extrema Ratio tactical knives and utility knives are distinguished by impeccable quality. Most knives are made from Austrian N690 steel. Extrema Ratio uses Böhler N690 due to its reliability and predictability. This steel is known for its increased content of molybdenum and cobalt and is characterized by high corrosion resistance. Thanks to this, N690 steel has increased strength and resists impact loads well, which is especially important for tactical use.

Popular Extrema Ratio knife models

The most popular Extrema Ratio knives are Fulcrum, Col Moschin, RAO, Adra. Extrema Ratio also produces several lines of tactical folding knives: BF (basic folder), MF (medium folder), BD4 and BD2 series. Folding models can also be used in urban conditions.

Frequently asked questions about Extrema Ratio knives


What does Extrema Ratio mean?

Extrema Ratio translated from Latin means “extreme measures”. The name reflects the philosophy of the brand: knives are created for situations where maximum reliability, control and readiness for extreme conditions are important.


Where are Extrema Ratio knives made?

Extrema Ratio knives are fully manufactured in Italy. The company is based in the city of Prato and controls the entire process — from development to assembly. The brand is an official supplier for military and law enforcement structures and has NATO supplier certification.


Which Extrema Ratio knife is used by the military?

One of the most well-known models is Col Moschin, developed for the 9th Parachute Assault Regiment of the Italian special forces. Models Fulcrum, Requiem and other knives created for specific unit tasks are also used.


Is it worth buying Extrema Ratio knives?

If you need an extremely strong and reliable knife for tactical tasks, outdoor or intensive use — yes. Extrema Ratio is a tool with a strength reserve, designed for real load. Extrema Ratio knives are also distinguished by the highest assembly quality. Over many years of our store’s operation, this brand has the lowest number of customer complaints regarding product quality.


In the MyGoodKnife online store you can buy original Extrema Ratio knives — we are an official dealer of the brand and offer only authentic products with worldwide shipping.