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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Folding knife Extrema Ratio MF1 Evo SP Tactical Mud 0410000233BLKTM 9.5cm
New
Folding knife Extrema Ratio MF1 Evo SP Tactical Mud 9.5cm 0410000233BLKTM
MF1 EVO SP Tactical Mud has a tactical mud handle and burnished Böhler N690 steel (58HRC). Spear Point blade. MF1 Evo is the evolution of Extrema Ratio MF1 knives series. The blade locking mechanism is the LINER-LOCK, supported by a new generation safety system “HIDDEN LOCK”. MF1 EVO SP Tactical Mud weights 187 g.  The handle is composed of two finely machined anodized aluminum scales.
€267.73

In stock

Folding knife Extrema Ratio MF1 Evo D Black 0410000232BLKBLK 9.5cm
Folding knife Extrema Ratio MF1 Evo D Black 9.5cm 0410000232BLKBLK
MF1 Evo is the evolution of Extrema Ratio MF1 knives series. This version has a black blade made ob Bohler N690 steel hardened to 58 HRC. Extrema Ratio MF1 Evo Black weights 187 g.  The handle is composed of two finely machined anodized aluminum scales. The grip is equipped with a hard metal rear glass-breaker. The blade locking mechanism is the LINER-LOCK, supported by a new generation safety system “HIDDEN LOCK”.
€221.51

In stock

Karambit knife Extrema Ratio K-Talon Dark Stone x Svechnikov Workshop 0410000224DKS 7cm
Fixed blade Knife Extrema Ratio K-Talon Dark Stone x Svechnikov Workshop 7cm 0410000224DKS
The Extrema Ratio K-Talon Dark Stone  is a fixed-blade karambit with a full-tang structure. It has a particularly thin shape with a thickness of only 10 mm including sheath and scales. The curved and hooked blade was inspired by the shape of a talon. It is designed to make clear and deep cuts as well as to hook, seize and/or tear. The ring in the back is built to gain a safe and firm grip in every situation. This way the knife does not slip and it makes it extremely difficult to disarm and point at the user.The very thin Kydex sheath has a quick release system and comes with a paracord that allows it to be worn as a neck knife and to be attached to the M.O.L.L.E. system. Custom handle is made of solid Walnut wood by Svechnikov Workshop. The set also includes original handle pads.
€292.43

In stock

Folding knife Extrema Ratio Ant Black 041000467BLKBLK 5cm
Folding knife Extrema Ratio Ant Black 5cm 041000467BLKBLK
Total black version of the Extrema Ratio Ant smallest EDC knife. This folding knife has 5 cm "sheepfoot" blade made of Bohler N690 steel. For easy carring Extrema Ratio Ant has a lanyard hole and a pocket clip. Pocket knife Ant is equipped with a small slot on the top to facilitate opening.
€101.99

In stock

Folding knife Extrema Ratio BF2 CT Stone Washed 04.1000.0146/SW 8.7cm
Folding knife Extrema Ratio BF2 CT Stone Washed 8.7cm 04.1000.0146/SW
Extrema Ratio BF2 CT is full sized folding knife with stone washed blade. The 87 mm blade is made of high quality Bohler N690 steel. The handle of Extrema Ratio BF CT knife has an aluminium scales. Knife has a secondary blocking system. Weight is 142 g.
€171.31

In stock

Fixed blade Knife Extrema Ratio Fat Boy Dark Stone x Svechnikov Workshop 0410000107OKS-BLKSV 21cm
Fixed blade Knife Extrema Ratio Fat Boy Dark Stone x Svechnikov Workshop 21cm 0410000107OKS-BLKSV
Exclusive! New amazing Extrema Ratio Fat Boy Dark Stone knife. It has 21 cm length blade made of N690 steel with a thickness of 8.6 mm. Weight of Extrema Ratio Fat Boy is 1 kg. Thanks to its generous size, Fat Boy is ideal for all heavy tasks. Custom handle is made of Scandinavian birch by Svechnikov Workshop. The set also includes original G10 handle pads. Fat Boy knife is equipped with a black Cordura sheath with MOLLE system. 
€676.49

In stock

Extrema Ratio Versa Expeditions 0410000214EXP 8cm
Extrema Ratio Versa Expeditions 8cm 0410000214EXP
Extrema Ratio Versa Expeditions is suitable as outdoor, survival and bushcraft knife. Versa has a full tang construction made of Bohler N690 steel with dark stone finish. 80 mm blade has a tanto profile. Weight is 110 g. Extrema Ratio Versa comes with kydex sheath.
€165.74

In stock

Fixed blade Knife Extrema Ratio S-THIL Stone Washed 04.1000.0223/SW 11.9cm
Fixed blade Knife Extrema Ratio S-THIL Stone Washed 11.9cm 0410000223SW
The Extrema Ratio S-THIL Stone Washed is a backup tactical knife of monolithic construction milled out of a 5 mm (0.2”) bar of BOHLER N690 steel, developed in cooperation with designer Thilo Arnd Schiller. The spear point blade is heat treated to 58 HRC for best combination of edge retention and toughness. It has a false double edge to make it very effective in thrusting and piercing and has a full length fuller that flows elegantly from the blade into the handle. The blade is milled integral to the knife for better compactness and lightness, with minimum thickness yet with a pattern that reminds of the classical Extrema Ratio knife grip. This profile creates two small guards and a comfortable thumb rest to prevent the hand from slipping towards the blade. On the pommel there is a diamond shaped skull crusher and a slot for a wrist strap or for giving the knife a paracord grip wrap. The stamped nylon sheath has been designed to be extremely flat and very narrow, to keep it as compact as possible. The tip of the sheath has a hole to allow debris or liquids to be expelled simply by blowing into it. The sheath can be used with belt clip, ULTICLIP or malice clip making it extremely versatile, while it is also possible to attach it to a M.O.L.L.E. webbing just by weaving paracord through it.
€158.17

In stock

Fixed blade Knife Extrema Ratio S-THIL Black Warfare 0410000223BWSE 11.9cm
Fixed blade Knife Extrema Ratio S-THIL Black Warfare 11.9cm 0410000223BWSE
Extrema Ratio S-THIL Black Warfare is a special version of the S-THIL model. Knife is made from a single piece of 5 mm thick BOHLER N690 steel, developed in collaboration with the designer Thilo Arnd Schiller. The spear point type blade. The special Black Warfare version of Extrema Ratio S-THIL uses the innovative and original Geotech Camo pattern, created by laser engraving.
€262.15

In stock

Fixed blade Knife Extrema Ratio Pugio SE Desert Warfare 04.1000.0317/DW 11cm
Fixed blade Knife Extrema Ratio Pugio SE Desert Warfare 11cm 0410000317DW
Extrema Ratio Pugio SE fixed knife in a compact size. The blade 110 mm (4.3 in) made of Böhler N690 steel. Desert Warfare pattern handle made of Forprene, with lanyard hole. Knife comes with hard belt sheath and BELT-CLIP. The sheath can be worn vertically, horizontally or obliquely (at a 45° angle). Overall length 226 mm (8.9 in). Weight 190 g (6.7 oz).
€264.52

Shipping after 10-20 business days

Tactical knife Extrema Ratio Fulcrum Compact Full handle DW 04.1000.0110/DW 11cm
Fixed blade Knife Extrema Ratio Fulcrum Compact Full handle DW 11cm 0410000110DW
Extrema Ratio Fulcrum Compact FH DW has a downsized blade 110 mm (4.33 in) and Forprene handle make it comfortable to carry and easily concealed. The included hard sheath can be worn vertically, horizontally or obliquely (at a 45° angle), and sports a single automatic pressure-activated security lock for quick, easier drawing and sheating. This makes the FULCRUM C an intuitive, rapid-use knife, ideally suited to emergencies or self-defense. The original version of the FULCRUM C comes with a 4.1in compact handle, the Full Handle version comes with a more comfortable 5in handle. Weight 258 g (9.10 oz)
€215.13

Shipping after 10-20 business days

Tactical knife Extrema Ratio Fulcrum Compact Desert Warfare 04.1000.0150/DW 11cm
Fixed blade Knife Extrema Ratio Fulcrum Compact Desert Warfare 11cm 04.1000.0150/DW
Fulcrum Compact Desert Warfare is the shorter version of the Fulcrum, which equals in robustness and sturdiness. Its downsized blade 110 mm (4.33 in) and Forprene handle 104 mm (4.1 in) with Desert warfare pattern make it comfortable to carry and easily concealed. The included hard sheath can be worn vertically, horizontally or obliquely (at a 45° angle), and sports a single automatic pressure-activated security lock for quick, easier drawing and sheating. This makes the FULCRUM C an intuitive, rapid-use knife, ideally suited to emergencies or self-defense. Weight 226 g (8 oz)
€215.13

Shipping after 10-20 business days

Tactical knife Extrema Ratio Corvo 04.1000.0442/BLK 17.6cm
Fixed blade Knife Extrema Ratio Corvo 17.6cm 0410000442BLK
The Corvo is a traditional Chilean Army combat knife. Its origins are misterious: it did probably arrive in the New World with the Spanish Conquistadores, who had already appreciated it during the war against the Moors. Corvo has been used during the War of the Pacific. It was produced in several versions such as: the Curved Corvo with the blade bending at almost 90° and the Corvo Atacameño combat knife which is longer but with a gentler bending of the blade for a higher flexibility during use. Extrema Ratio has been inspired by this second version.The black blade 176 mm (6.92 in) is made of Böhler N690 steel. Forprene handle. Total length 307 mm (12.08in) Weight  362 g (12.76 oz)
€285.20

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Tactical knife Extrema Ratio Contact HCS 04.1000.0215/HCS 16.2cm
Fixed blade Knife Extrema Ratio Contact HCS 16.2cm 0410000215HCS
Extrema Ratio Contact HCS version. It has a stonewash 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

Shipping after 10-20 business days

Tactical knife Extrema Ratio Col Moschin Black Collector Edition 04.1000.0125/BLK-CE 15cm
Fixed blade Knife Extrema Ratio Col Moschin Black Collector Edition 15cm 0410000125BLKCE
Now available also in the Collector Edition version with special plexiglass diplay case. 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.
€570.39

Shipping after 10-20 business days

Tactical knife Extrema Ratio 39-09 Special Edition 04.1000.0339/SAT-SE 19.5cm
Fixed blade Knife Extrema Ratio 39-09 Special Edition 19.5cm 04.1000.0339/SAT-SE
This Extrema Ratio 39-09 Special Edition 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 – not to mention advocated for by knife collectors worldwide – this combat knife 39-09 is a restyling of the Model 1939 “paracadutista assaltatore” (assault paratrooper) knife, a celebrated piece of Italian military history. The included hard sheath is designed to be worn at the ankle, in the characteristic fashion of Italian paratroopers. The 39-09 SPECIAL EDITION version, numbered, unlimited edition, has wooden hilt, satin-finish blade. It comes in a black wooden case, including a parade belt sheath. 
€643.00

Shipping after 10-20 business days

Fat Boy Dark Stone
Fixed blade Knife Extrema Ratio Fat Boy Dark Stone 21cm 0410000107OKS-BLK
New amazing Extrema Ratio Fat Boy Dark Stone knife. It has 21 cm length blade made of N690 steel with a thickness of 8.6 mm. Weight of Extrema Ratio Fat Boy is 1 kg. Thanks to its generous size, Fat Boy is ideal for all heavy tasks. The handle is composed of two black G10 scales. Fat Boy knife is equipped with a black Cordura sheath with MOLLE system. Available also in satin version.
€589.62

Shipping after 10-20 business days

Fixed blade Knife Extrema Ratio Fat Boy Satin 0410000107SAT-BLK 21cm
Fixed blade Knife Extrema Ratio Fat Boy Satin 21cm 0410000107SAT-BLK
A long-awaited new product - a unique Extrema Ratio Fat Boy knife. This is the version with a satin finish blade. Fat Boy is the most robust fixed blade knife ever produced by Extrema Ratio.  It has 21 cm length blade. This is the first model produced in N690 steel (58HRC) with a thickness of 8.6 mm, for a total weight of 1 kg. Thanks to its generous size, Fat Boy is ideal for all heavy jobs, from splitting to disengagement in extreme scenarios, allowing you to carry out different activities, including levering to open doors, car doors and windows. The handle is composed of two black G10 scales, featuring a new original Extrema Ratio design. They can be removed and replaced. Fat Boy knife is equipped with a black Cordura sheath with an anti-cutting rubber blade lock. The MOLLE system on both sides can be used by both right-handed and left-handed.
€589.62

In stock

Neck knife Extrema Ratio Kiri Dark Stone 04.1000.0187/BLK-SW 6cm
Fixed blade Knife Extrema Ratio Kiri Dark Stone 6cm 0410000187BLKSW
Neck knife Extrema Ratio Kiri Dark Stone 04.1000.0187/BLK-SW with 6cm blade. Kiridashi is a type of Japanese knife, a cutting multipurpose tool. Its asymmetric bevel, where only one of the two sides is ground and the other is left flat, is one of its features. This traditional Japanese knife has been recreated by Extrema Ratio in accordance with its style, giving it a more tactical appearance than the original. Both the Dark Stone and Satin finishes, made of Böhler N690 steel hardened to 58 HRC, are offered for the Extrema Ratio KIRI.
Two black anodized anticorodal metal scales make up the handle. The metal eyelets on the pre-shaped Kydex sheath allow you to attach it to an M.O.L.L.E. system webbing and insert a paracord.
€215.94

In stock

Neck knife Extrema Ratio Kiri Satin 04.1000.0187/SAT 6cm
Fixed blade Knife Extrema Ratio Kiri Satin 6cm 04.1000.0187/SAT
Neck knife Extrema Ratio Kiri Satin with 6cm blade. Kiridashi is a type of Japanese knife, a cutting multipurpose tool. Its asymmetric bevel, where only one of the two sides is ground and the other is left flat, is one of its features. This traditional Japanese knife has been recreated by Extrema Ratio in accordance with its style, giving it a more tactical appearance than the original. Both the Dark Stone and Satin finishes, made of Böhler N690 steel hardened to 58 HRC, are offered for the Extrema Ratio KIRI.
Two black anodized anticorodal metal scales make up the handle. The metal eyelets on the pre-shaped Kydex sheath allow you to attach it to an M.O.L.L.E. system webbing and insert a paracord.
€205.56

In stock

Tactical knife Extrema Ratio Contact C Desert
Fixed blade Knife Extrema Ratio Contact C Desert 12.8cm 0410000216DW
Extrema Ratio Contact C Desert has a Böhler N690 steel spearpoint blade, hardened at 58 HRC. The injection molded, impact grade nylon, M.O.L.L.E. compatible scabbard. Extrema Ratio Contact C Desert weights 273 g. 
€185.48

Shipping after 10-20 business days

Tactical knife Extrema Ratio Pugio Black 0410000314BLK 11cm
Fixed blade Knife Extrema Ratio Pugio Black 11cm 0410000314BLK
Though named after a short and pointed Roman dagger, our own Extrema Ratio Pugio Black  sports a cuttlebone-shaped hilt reminiscent of the longer Caucasian knives. Ir’s a boot dagger, a delf-defense backup weapon excellently suited for concealed carry. The blade is hollow ground, while absence of guard prevents accidental entanglement in close quarters. Includes an easy-locking BELT-CLIP hard sheath, adjustable for carrying the knife vertically, horizontally or obliquely (at a 45° angle).
€251.79

In stock

Rescue knife Extrema Ratio Ferrum Rescue Red 04.1000.0365
Rescue knife Extrema Ratio Ferrum Rescue Red 5.6cm 0410000365SWRED
Ferrum Rescue Red is a product designed for intensive use, developed in collaboration with Andrea Micheli. The handle is made of anodized anti-corrosion aluminum. The first serrated blade allows it to cut through larger ropes or fabrics, while the smooth edge acts like a real knife. The second blade is a scalpel that can be used to make very precise cuts and perform emergency procedures. The third and smallest one, located on the back of the main blade, is a cord cutter that can also be used to cut aramid paracord. Locking mechanism - LinerLock. The model has a reversible clip.
€233.87

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.