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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Tactical knife Extrema Ratio Contact C Wolf Grey
Fixed blade Knife Extrema Ratio Contact C Wolf Grey 12.8cm 0410000216WG
Compact version of the CONTACT, the Contact C Wolf Grey from Extrema Ratio has a Böhler N690 stainless steel spearpoint blade, hardened at 58 HRC with single branch handguard and full length fuller for lightness. The Forprene grip is affixed by a threaded tang that makes the knife sturdy and well balanced. The injection molded, impact grade nylon, M.O.L.L.E. compatible scabbard has a dampening system to avoid blade rattle, twin button safety loop and a retention safety disengaged by simple pressure on the trigger-like lever.
€183.27

Shipping after 10-20 business days

Tactical knife Extrema Ratio Contact C HCS
Fixed blade Knife Extrema Ratio Contact C HCS 12.8cm 0410000216HCS
Knife Extrema Ratio Contact C HCS comes with forprene handle. Knife has a Böhler N690 steel spearpoint blade, hardened at 58 HRC with single branch handguard and full length fuller for lightness. The Forprene grip is affixed by a threaded tang that makes the knife sturdy and well balanced. The injection molded, impact grade nylon, M.O.L.L.E. compatible scabbard has a dampening system to avoid blade rattle, twin button safety loop and a retention safety disengaged by simple pressure on the trigger-like lever.
€185.48

Shipping after 10-20 business days

Tactical knife Extrema Ratio Fulcrum Desert Warfare
Fixed blade Knife Extrema Ratio Fulcrum Desert Warfare 18cm 0410000082DW
The Extrema Ratio Fulcrum’s Desert Warfare blade can sustain loads of over 150 kilograms without breaking. Blade length is 180 mm. The tanto-shaped blade allows for large amounts of work and wear while still retaining a sharp, penetrating edge at its exceedingly sturdy tip. Thanks to its weight and top-heavy balancing, the Fulcrum is also suitable for hard work on the field. 
€305.95

In stock

Tactical knife Extrema Ratio Contact Wolf Grey
Fixed blade Knife Extrema Ratio Contact Wolf Grey 16.2cm 0410000215WG
The elegant and reliable Extrema Ratio Contact Wolf Grey knife is the first model from the new line of full–size Extrema Ratio tactical knives. The knife received a 16.2-centimeter Spear Point profile blade made of BöHLER N690 steel with a hardening level of up to 58 units on the Rockwell hardness scale. The knife has universal performance characteristics and resistance to extreme loads. The handle of the Contact tactical knife is made of Forprene thermoplastic material. Weight 300 g. Extrema Ratio Contact is equipped with wear-resistant nylon sheath compatible with M.O.L.L.E. systems.
€226.61

In stock

Tactical knife Extrema Ratio Contact Ranger Green
New
Fixed blade Knife Extrema Ratio Contact Ranger Green 16.2cm 0410000215GRN
The Extrema Ratio Contact Ranger Green knife is the first model from the new line of full–size tactical knives Extrema Ratio. The knife has universal performance characteristics and resistance to extreme loads. The knife received a 16.2-centimeter Spear Point profile blade made of BöHLER N690 steel with a hardening level of up to 58 units on the Rockwell hardness scale. The handle of the Contact tactical knife is made of Forprene thermoplastic material. Weight 300 g. Extrema Ratio Contact is equipped with wear-resistant nylon sheath compatible with M.O.L.L.E. systems.
€241.43

In stock

Tactical knife Extrema Ratio Contact C Black
Fixed blade Knife Extrema Ratio Contact C Black 12.8cm 0410000216BLK
Extrema Ratio Contact C Black has a Böhler N690 steel spearpoint blade, hardened at 58 HRC with single branch handguard and full length fuller for lightness. The Forprene grip is affixed by a threaded tang that makes the knife sturdy and well balanced. The injection molded, impact grade nylon, M.O.L.L.E. compatible scabbard has a dampening system to avoid blade rattle, twin button safety loop and a retention safety disengaged by simple pressure on the trigger-like lever.
€212.75

In stock

Tactical knife Extrema Ratio DMP Desert
Fixed blade Knife Extrema Ratio DMP Desert 15.2cm 0410000219DW
Extrema Ratio DMP Desert is a multipurpose fixed blade knife. The drop point blade has length 152 mm. Blade is made of Bohler N690 steel. The sheath has a reversible system for ambidextrous users. Extrema Ratio DMP has handy forprene handle. 
€217.51

In stock

Hunting and Outdoor knife Extrema Ratio Dobermann IV Classic 04.1000.0184/SAT 18.5cm - 1
Fixed blade Knife Extrema Ratio Dobermann IV Classic 18.5cm 04.1000.0184/SAT
DOBERMANN IV evolved from the first and most classic Extrema Ratio knife, the K1 DOBERMANN. Over the years, the DOBERMANN has undergone significant change in look and design to meet evolving consumer expectations and ever-changing trends, while at its core retaining consistency with the original 1997 design. This last iteration, too, excels at structural durability and flexibility of use: perhaps our most versatile knife, the DOBERMANN IV is suitable for hunting, outdoors survival, camping, defense, up to and encompassing military use. There are only best fixed blade knives in MyGoodKnife's range.
€368.55

Shipping after 10-20 business days

Tactical knife Extrema Ratio A.M.F. Deser
Fixed blade Knife Extrema Ratio A.M.F. Desert 20.6cm 04.1000.0485/DW
A.M.F. (Advanced Multi Function) is a 20,6 cm blade knife inspired to a legend in the survival cutlery of the 80es. It can be easily disassembled. It comes with cordura sheath fitting the M.O.L.L.E. system. A survival kit (to be bought only on request) can be easily fixed to the cordura sheath. A.M.F. comes in black and in desert version
€327.42

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Folding knife Extrema Ratio RAO II Expeditions
Folding knife Extrema Ratio RAO II Expeditions 11.9cm 0410000136EXP
RAO II Expeditions is a heavy and useful tool. It has a desert-coloured aluminum handle and sheath. Blade is made of Bohler N690 (58HRC) steel with a special finishing. Rao II Expeditions has ergonomic handle scales with rounded upper angles, and a drop point blade. The new Expedition Series folding knife can be easily used for heavy duties also thanks to its extremely sturdy locking mechanism, which is supported by a safety that turns it into a proper fixed blade. There is a threaded steel pin to be hand-screwed through two holes by the guard section of the massive aluminum handle.
€342.74

In stock

Folding knife Extrema Ratio RAO II
Folding knife Extrema Ratio RAO II 11.9cm 04.1000.0136/BLK
The Extrema Ratio RAO II is a new version of the famous Extrema Ratio RAO knife; it comes with a new drop-point blade and an improved handle that is rounded at the top corners for a more ergonomic grip. The extra safety lock transforms the RAO II into a fixed blade knife for high performance without risk of injury. The sheath can hold the knife open for frequent use or closed in the front pocket. It comes with a diamond sharpener to always have a perfect cutting edge.
€334.68

Shipping after 10-20 business days

Folding knife Extrema Ratio Caimano Nero N.A
Folding knife Extrema Ratio Caimano Nero N.A. 9.3cm 0410000166BLK
It is the non-automatic version of the tactical knife that Extrema Ratio has supplied to the G.O.I. (Operational Raiders Group) of the Italian Navy. The blade is a 4 mm thick asymmetrical spear point. The serrated part of the edge allows to cut highly-resistant cables and fabrics without losing its sharpening. The bottom part of the handle is designed to enhance the grip for a rapid extraction of the knife from the pocket. It is also equipped with a hard-metal glass breaker. The DLC-coated titanium clip can be positioned in three different angles on both sides allowing to conceal the knife as much as possible inside the pocket.
€274.90

In stock

Neck knife Extrema Ratio N.K.3 Stone washed 04.1000.0206/SW 7cm
Fixed blade Knife Extrema Ratio N.K.3 Stone washed 7cm 04.1000.0206/SW
N.K.3 is a reduced-size knife that enlargesis the family of neck knives by Extrema Ratio. N.K.3 is bigger than both N.K.1 and N.K.2, featuring a tanto blade 70mm long and the blood-draining slot. The design of the handle prevents accidental injury while drawing. A groove on the back of the blade accommodates for the user’s index finger or thumb, according to wielding style. Due to its overall construction, the N.K.3 is both capable of offense, through very effective slashing strikes, and useful for minute precision work. The included, rapid- release Kydex sheath comes with a paracord strip for neck carry. Further, it can be attached via MOLLE system to tactical vests or to any of the compatible cordura sheaths from Extrema Ratio. Available but not included: BELT-CLIP (for attaching sheath to a belt), polymer UNDER SHIRT SYSTEM (for concealed carry). There are only best fixed blade knives in MyGoodKnife's range.
€130.65

Shipping after 10-20 business days

Tactical knife 434 - Extrema Ratio Fulcrum S Desert Warfare 04.1000.0092-DW 15cm
Fixed blade Knife Extrema Ratio Fulcrum S Desert Warfare 15cm 0410000092DW
Extrema Ratio Fulcrum S Desert Warfare is a shorter version of the famous Fulcrum knife. It has a 15 cm (5.91”) blade. Same qualities of the FULCRUM except for a lighter mass to bring to bear in performing hard work. Weight of Extrema Ratio Fulcrum S Desert Warfare is 304g. 
€301.90

In stock

Dagger Extrema Ratio Nimbus Special Edition
Fixed blade Knife Extrema Ratio Nimbus Special Edition 14.1cm 0410000240SAT-SE
The tactical knife Extrema Ratio Nimbus Special Edition  is a modern version of the Second World War Italian Nimbus assault knife. The Special Edition comes with wooden handle, satin blade, leather sheath and leather special case. The 141mm (5.55") tactical blade is light and compact for ease of use and is made from Böhler N690 steel. The total length of the Nimbus knife is 263 mm (10.35 in). 
This knife celebrates the battle of Case Grizzano which took place on 19th April 1945 between the paratroopers of Nembo and the German 1 Division Fallschirmjäger “Green Devils”, a 12 hours extremely cruel and bloody hand-to-hand blade skirmish.
€606.34

In stock

Folding knife Extrema Ratio BDØ R Black
Folding knife Extrema Ratio BD0 R Black 6cm 0410000459BLKSW
BD0 R Black from Extrema Ratio is a new knife designed for lightness. It is characterized by a very slim profile with a focus on lightness. The blade is made in Bohler N690 steel hardened to 58 HRC, 2.36” (60mm) long, 0.1” (2.5 mm) thick, with a plain sharpening and a faux edge on the first third of the spine. The blade is deployed by the usual “Razor” tang extension which enables effortless ambidextrous operation. A simple yet sturdy liner lock system holds the blade open. The reversible clip with lightening holes contributes to maintain the weight of the knife to a minimum. With an overall length of 5.7” (165 mm) and a weight of just  52 g the Extrema Ratio BD0 R is an extremely light and slim knife which makes it an ideal EDC choice.
€78.23

In stock

Folding knife Extrema Ratio RAO Avio Black
Folding knife Extrema Ratio RAO Avio Black 11.9cm 0410000141BLK G
Extrema Ratio RAO Avio Black is the survival version of RAO knife chosen by the Italian Air Force to complement the equipment package. Blade length is 119 mm. Blade is made of Bohler N690 steel. The improved survival kit includes: whistle, pocket chain saw, water purifying tabs, compass, copper wire, flint and fire striker, LED light, 2.5 mts paracord and diamond-plate sharpener. The sheath holds the knife in open position. The kit is contained in a pocket fastened to the sheath by a MOLLE system.
€401.61

In stock

Tactical knife Extrema Ratio Misericordia Desert
Folding knife Extrema Ratio Frame Rock Titan Black 7.5cm 0410000456BLKTIT
Extrema Ratio Frame Rock Titan Black is a new knife, based on the design of the Ti-Rock, a successful framelock custom made knife that Extrema Ratio has realized for a renowned Italian distributor. Spear point blade 75 mm is made of high quality Bohler N690 steel, with black DLC treatmet finish. The handle is equipped with a pocket clip. Opening the blade is smooth and easy thanks to the bearings. This mechanism allows the user to adjust the force required to release the blade with the screw. Framelock. The knife weighs about 270 g. Made in Italy. It comes with a special ABS case.
€441.93

In stock

Folding knife Extrema Ratio BDØ R Wolf Grey
Folding knife Extrema Ratio BD0 R Wolf Grey 6cm 0410000459WG
Extrema Ratio BD0 R Wolf Grey is a new and elegant knife designed for lightness. With an overall length of 5.7” (165 mm) and a weight of just  52 g the Extrema Ratio BDØ R is an extremely light and slim knife which makes it an ideal EDC choice. It is characterized by a very slim profile with a focus on lightness. The blade is made in Bohler N690 steel hardened to 58 HRC, 2.36” (60mm) long, 0.1” (2.5 mm) thick, with a plain sharpening and a faux edge on the first third of the spine. The blade is deployed by the usual “Razor” tang extension which enables effortless ambidextrous operation. A simple yet sturdy liner lock system holds the blade open. The reversible clip with lightening holes contributes to maintain the weight of the knife to a minimum. 
€79.03

In stock

Folding knife Extrema Ratio BDØ R HCS
Folding knife Extrema Ratio BD0 R HCS 6cm 0410000459HCS
BD0 R HCS from Extrema Ratio is a new knife designed for lightness. It is characterized by a very slim profile with a focus on lightness. The blade is made in Bohler N690 steel hardened to 58 HRC, 2.36” (60mm) long, 0.1” (2.5 mm) thick, with a plain sharpening and a faux edge on the first third of the spine. The blade is deployed by the usual “Razor” tang extension which enables effortless ambidextrous operation. A simple yet sturdy liner lock system holds the blade open. The reversible clip with lightening holes contributes to maintain the weight of the knife to a minimum. With an overall length of 5.7” (165 mm) and a weight of just  52 g the Extrema Ratio BD0 R is an extremely light and slim knife which makes it an ideal EDC choice.
€78.23

In stock

Survival knife Extrema Ratio RAO Desert Warfare
Survival knife Extrema Ratio RAO Desert Warfare 11.9cm 0410000141DW
Tactical folding knife Extrema Ratio RAO Desert Warfare with a blade length of 11.9 cm. 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: 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. The sheath can be attached to tactical vests or common belts, being MOLLE system--compliant.
€345.16

In stock

Tactical knife Extrema Ratio Fulcrum
Fixed blade Knife Extrema Ratio Fulcrum E.I. 18cm 0410000082BLK-EI
 Extrema Ratio Fulcrum E.I. has black 18 cm blade  made of Bohler N690 steel. The blade can sustain loads of over 150 kilograms without breaking. The tanto-shaped blade allows for large amounts of work and wear while still retaining a sharp, penetrating edge at its exceedingly sturdy tip. Thanks to its weight and top-heavy balancing, the Fulcrum is also suitable for hard work on the field. 
€299.19

In stock

Tactical knife Extrema Ratio 39-09 Ordinanza COFS
Fixed blade Knife Extrema Ratio 39-09 Ordinanza COFS 19.5cm 0410000339BLK-OR
Extrema Ration 39-09 Ordinanza is the result of a project sponsored by COFS (the inter-force operations command for Italian special forces) and its former Commander-in-chief, Gen. Bertolini. This combat knife 39-09 is a restyling of the Model 1939 “paracadutista assaltatore” (assault paratrooper) knife, a celebrated piece of Italian military history. Small changes which make it a highly effective, dependable dagger. The included hard sheath is designed to be worn at the ankle, in the characteristic fashion of Italian paratroopers. The 39-09 Ordinanza version has Forprene handle, black oxide-coated with COFS logo & motto. It comes in ABS engraved case with an ankle sheath and a parade belt sheath. Weight  338 g (11.9 oz)
€496.39

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.