Extrema Ratio
Extrema Ratio handle scales
Extrema Ratio, an Italian premium knife brand specializing in military knives, tactical folders, and professional blades, was founded on November 17, 1997, in Prato, Italy, by Mauro Chiostri and Maurizio Castrati. The two longtime friends combined their skills and passion to build a company from scratch, starting with sport and utility knives before pivoting to high-performance military designs
Early success came from contracts with special units of the Italian Army, providing technical feedback that shaped Extrema Ratio's uncompromising quality standards—blending industrial processes with handcrafted finishing like manual sharpening for reliability and precision
Key milestones include supplying elite forces worldwide, adopting Böhler N690 and Niolox steels, and developing iconic models like the RAO, Gladio, Col Moschin, and bayonets for programs such as France's FELIN soldier system. By its 25th anniversary in 2022, Extrema Ratio had earned global recognition for extreme durability, innovative ergonomics, and professional-grade craftsmanship in tactical knives, combat knives, and survival blades—remaining 100% Italian-owned and focused on military, law enforcement, and rescue users