Extrema Ratio
Shop Extrema Ratio knives at Atlantic Knife, including fixed blades, folding knives, EDC designs, tactical knives, outdoor knives, tantos, bayonets, self-defense tools and limited-edition collector pieces. Designed and made in Prato, Italy, Extrema Ratio combines modern precision engineering with traditional craftsmanship. Its knives are trusted by military and law-enforcement professionals, serious outdoor users, collectors and everyday carriers who expect dependable performance and unmistakable Italian design.
Explore hard-use models featuring premium steels such as Böhler N690, MagnaCut, M390 and Extrema Ratio’s specialized nitrogen steels. Available designs range from compact pocket knives and neck knives to full-size fixed blades, field tools and serialized limited editions. Atlantic Knife offers an expanding Extrema Ratio selection and knowledgeable service to help you choose the right model. Shop the collection below, or explore our Extrema Ratio brand page for release stories, detailed comparisons, videos and a closer look at the craftsmanship behind the knives.
